How do you solve linear equations with substitutions?

Answers

Answer 1

Answer:

The method of solving "by substitution" works by solving one of the equations (you choose which one) for one of the variables (you choose which one), and then plugging this back into the other equation, "substituting" for the chosen variable and solving for the other. Then you back-solve for the first variable.

Step-by-step explanation:

Solve the following system by substitution.

2x – 3y = –2

4x +   y = 24

The idea here is to solve one of the equations for one of the variables, and plug this into the other equation. It does not matter which equation or which variable you pick. There is no right or wrong choice; the answer will be the same, regardless. But — some choices may be better than others.

For instance, in this case, can you see that it would probably be simplest to solve the second equation for "y =", since there is already a y floating around loose in the middle there? I could solve the first equation for either variable, but I'd get fractions, and solving the second equation for x would also give me fractions. It wouldn't be "wrong" to make a different choice, but it would probably be more difficult. Being lazy, I'll solve the second equation for y:

4x + y = 24

y = –4x + 24

Now I'll plug this in ("substitute it") for "y" in the first equation, and solve for x:

2x – 3(–4x + 24) = –2

2x + 12x – 72 = –2

14x = 70

x = 5


Related Questions

Can someone help me with this question it’s 7.55 x 4.5

Answers

Answer:

33.975

Step-by-step explanation:

If you are going to multiply this by hand, make sure that you add a zero to the end of 4.5 so that it is 4.50. Because there are four decimal places, you need to make sure your answer has four decimal places as well. Then add a row of zeroes to the bottom because anything times zero equals zero. Next, add a zero in the hundredths place and multiply 5 from 4.50 to 7.55. Then, do the same with the 4. Add all your numbers together and you should get 33.9750 or 33.975.

what is tan 30 degrees?
look at photo
i’ll give brainliest

Answers

The answer is e because tan 30 = 57735027 and 1/^3= 57735027

If John can paint half of a room in two-thirds of an hour, what part of the room can he paint in a full hour?

Answers

Answer:

0.75(3/4) part of the room

Step-by-step explanation:

Step one:

given data

we can express the given data mathematically as

John can paint 0.5room in 2/3 hours

let the part of the room he can paint in an hour be x

so

if he takes 2/3 hours to paint 0.5 room

then he will take 1 hour to paint x

cross multiply we have

x= 0.5/2/3

x=0.5*3/2

x= 1.5/2

x=0.75 part of the room

75/100= 15/20=3/4 part

On a map, a city block is a square with three vertices at (-4,1), (1,1), and (1,-4). What are the remaining coordinates of the remaining vertex ?

Answers

Answer:

(-4, -4)

Step-by-step explanation:

Maria got 50% of the questions correct on her science test. If she got 32 questions correct, how
many questions were on the exam?

Answers

Answer:

64

Step-by-step explanation:

:)

Answer:

64 Questions

Step-by-step explanation

50% x 2 = 100%

32 x 2 = 64

HELP ASAPPPP!!!!!!!!!!!!!!!!!!

Answers

Hdhdbddbr. Dhdhddbdhdbe evehheehbd

Can someone help me with those and explain please. Ill give brainlist

Answers

Answer:

1. 23x/10

2. 13x/10

Step-by-step explanation:

explanation: find the common denominator and then go from there. i suck at in depth explanations but as long as you get the gist of it youre good

What is 50% of a dollar
HELP ME FAST

Answers

Answer:

50 cents

(⓿_⓿)

df/ dt = lim f( t + h ) - f(t)
______________
h

Answers

Answer:

boi

Step-by-step explanation:

An airline knows that 9 out 50 passengers who book a flight do not show up. If 300 people booked a flight , how many will not show up?

A) 45 passengers
B) 54 passengers
C) 100 passengers
D) 27 passengers

Answers

Answer:

300 divided by 50 is 6. 6 x 9 is 54. your answer is B)54

Step-by-step explanation:

Does anyone know how to do part b?

Answers

Answer:

No

Step-by-step explanation:

2x+5=17 I need help :(((((((

Answers

Answer:

the answer is 6

Step-by-step explanation:

the first thing you need to do is take 5 away from 17 to get 12 2x=12 then you need to divide 2 from both

Answer:
X=6
Explanation:

x^2+ 5x – 6.

A.)(x-1)(x+6)
B.)(x+1)(x-6)
C.)(X-2)(x-3)
D.)(x-2)(x*3)

Answers

Answer:

A bruh

Step-by-step explanation:

trust the process

What is the slope of the line perpendicular to the line represented by the equation y = 4x - 7? *
a)-1/4
b)-7
c) 4
d)-4

Answers

Answer: im kinda losing brain cells rn

Step-by-step explanation:

Answer:

Step-by-step explanation:

c

Please help me really quick! :DD

Answers

Answer:

Correct equation: 4b^2 -b-138= 0

Solution: 6 meters

Step-by-step explanation:

The base has to be 6, and that’s the equation that works with that number.

Examine the following table of points, which are all on a certain line.

x y

−2 4

0 2

1 1

3 −1


What is the slope of this line?


Enter your answer as a number, like this: 42


Or, if the slope is undefined, enter a lowercase letter "u," like this: u

Answers

9514 1404 393

Answer:

  -1

Step-by-step explanation:

The slope formula is useful:

  m = (y2 -y1)/(x2 -x1)

  m = (2 -4)/(0 -(-2)) = -2/2 = -1

The slope of this line is -1.

_____

The points on the line drop 1 unit for each 1 unit to the right.

  m = rise/run = -1/1 = -1

The following table gives the mean scores for 4 different classes
on the same test.
Class A Class B Class C Class D
72% 82% 63% 78%
What is the combined average for classes A, B, C and D, if
class A has 30 students, class B has 22 students, class C has
35 students, and class D has 27 students?
A
73.8%
73.5%
B
72.6%
D = 71.9%

Answers

Answer:

a

Step-by-step explanation:

a

The answer is to that question is Class A

WILL GIVE BRAINLIEST write an equation for the nth term of the sentence and find the 91st term -2,3,8,13,...

Answers

Answer:

y=X+5?

Step-by-step explanation:

This is a hard one but this may be correct

Which of these could you represent with a ratio? A how many diet sodas there are in the fridge compared to how many regular sodas B the average age of writers for a newspaper C the maximum number of people that can fit inside an elevator D how many square feet of carpet are needed to completely cover the floor

Answers

Answer:

a

Step-by-step explanation:

Each morning, Stacey makes 20 cinnamon bagels for his customers at Barney's Bagels. Because of a recent increase in the popularity of cinnamon bagels, she has increased the number she bakes each morning by 80%. How many cinnamon bagels does Stacey now bake each day?

Answers

Answer: Stacey now bakes 36 cinnamon bagels.

Step-by-step explanation:

Given:  Each morning, Stacey makes 20 cinnamon bagels.

She has increased the number she bakes each morning by 80%.

Number of cinnamon bagels Stacey bake = 20+80% of  20

= 20+ (0.80)x 20           [To remove % , divide number by 100, So 80%=0.08]

= 20+16   [(0.80)x 20=16 ]

= 36

Hence, Stacey now bakes 36 cinnamon bagels.

What is the solution to the equation 6x - 5 =15
X = 5/6
X = 5/3
X = 10/3
I don’t know

Plz I need this

Answers

Answer:

x=10/3

Step-by-step explanation:

step 1: add five to both sides to get rid of the -5.

step 2: divide 6 on both sides to isolate the variable

step 3: simplify 20/6 by finding the greatest common factor which is 2.

Answer:

5/3

Step-by-step explanation:

I believe it's the answer because 15 minus 5 is 10 and if you divide it its 3 over 5 but its switched here so your answer is 5/3

(3,-1) slope= 2 what is the equation?​

Answers

Answer:

y = 2x - 7

Step-by-step explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Here m = 2, thus

y = 2x + c ← is the partial equation

To find c substitute (3, - 1) into the partial equation

- 1 = 6 + c ⇒ c = - 1 - 6 = - 7

y = 2x - 7 ← equation of line

Robert has been riding his bike at a constant speed for the last 35 minutes. If Robert is traveling at a speed of 9 miles per hour, which equation best represents this relationship between the time in hours, t, and the distance in miles, d?

Answers

Answer:

A

Step-by-step explanation:

I looked it up

HELPPP FASTTT PLEASEEEEEEEEEE

Answers

HI is 9 because all angles congruent.

Angle k is 110 degrees because the two sides are equal, their angles are equal. So you have 35+35=70. Angles of triangle add to 180, so subtract 70 from 180 to get 110.

Use a​ table, an​ equation, and a graph to represent the relationship below.
Ty is 6 years younger than Bea.

Answers

Answer:

Ukwkwkw

Step-by-step explanation:

Answer:

b-6=t  

Step-by-step explanation:

if the solutions of p(x)=0 are -14 and 11, which function could be p?
(A) p(x)=x^2-3x-154

(B) p(x)=x^2-14x+11

(C) p(x)=x^2+14x+11

(D) p(x)=x^2+3x-154

Answers

Answer:d

Step-by-step explanation:

The required function is [tex]P(x)=x^2+3x+154[/tex]. So, option D is correct.

Important information:

The solutions of [tex]p(x)=0[/tex] are [tex]-14[/tex] and 11.

We need to find the function p(x).

Function:

If [tex]x=c[/tex] is a solution of [tex]p(x)=0[/tex], then [tex](x-c)[/tex] is a factor of p(x).

It means [tex](x+14)[/tex] and [tex](x-11)[/tex] are two factor of p(x).

[tex]P(x)=(x+14)(x-11)[/tex]

[tex]P(x)=x^2-11x+14x+154[/tex]

[tex]P(x)=x^2+3x+154[/tex]

Therefore, the correct option is D.

Find out more about 'Function' here:

https://brainly.com/question/19446232

Alexandro received two quotes for new carpet for his home. The quote from Home Depot is $0.20 less per square foot than the quote from Lowe's. If Alexandro plans to buy 1,300 square feet of carpet, how do his total costs from the two companies compare? *

Answers

Answer:

Total cost as per Lowe's is $260 more than that of Home Depot.

Step-by-step explanation:

Given that:

Alexandro received two quotes for new carpet.

One from Home Depot and other from Lowe's.

Let quote from Home Depot = [tex]\$x[/tex] per sq foot

As per question statement,

The quote from Lowe's = [tex]\$x[/tex]+0.20 per sq foot

Alexandro plans to buy 1,300 square feet of carpet.

Total Cost as per Home Depot's quote = [tex]\$1300x[/tex]

Total Cost as per Lowe's = [tex]\$(x+0.20)\times 1300 = \$1300x + \$260[/tex]

Now taking the difference of the total cost:

Lowe's total cost - Total cost as per Home Depot.

[tex]\$1300x+\$260 - \$1300x \\\Rightarrow \$260[/tex]

So, the answer is:

Total cost as per Lowe's is $260 more than that of Home Depot.

A number minus seven is nine.

Answers

Answer:

Your answer would be 16 - 7 = 9.

You can simply add the two numbers and it would still give you the same answer, but I decided to just look for the number.

Step-by-step explanation:

I hope this helped solve your question.

(-3,3)
y
1
(12, -3)
What is the slope of the line shown?

Answers

Answer:USE GOOGLE

Step-by-step explanation:

I USE IT EVERY DAY

Answer:

7/5

Step-by-step explanation:

*******************

130-y=224
solve for y

Answers

Answer:

Y = -94

Step-by-step explanation:

130 - y = 224     -subtarct 130

-y = 94        -multiply by -1

y = -94

Hope this helps. Pls give brainliest.

Answer:

y = -94

Step-by-step explanation:

130 - y = 224

subtract 130 from both sides

130 - 130 - y = 224 - 130

-y = 94

u want y not -y so divide both sides with "-"

y = -94

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