For khan academy. Need help immediately. Explain if you can

Answer:

D

Step-by-step explanation: So, multiplying two rationals is the same as multiplying two such fractions, which will result in another fraction of this same form since integers are closed under multiplication. Thus, multiplying two rational numbers produces another rational number.

Answer:

The product of a rational number and an irrational number is irrational.

Step-by-step explanation:

The product of a rational number and an irrational number is irrational. For example, let p= 1 be a rational number and q= 3.567be an irrational number if multiplied together the result would be 3.567, which is an irrational number.

Hope this helped!

Answer:

-1.23

Step-by-step explanation:

-0.3 x 4.1 = -1.23.

A negative number times a positive number equals a negative number.

Answer:

C

Step-by-step explanation:

Answer:

C. [tex]\frac{1}{49}[/tex]

Step-by-step explanation:

When one puts a number to a negative exponent, such as;

[tex]a^{-b}[/tex]

One is essentially doing;

[tex]\frac{1}{a^{b}}[/tex]

Applying that knowledge;

[tex]7^{-2} \\= \frac{1}{7^{2}}\\= \frac{1}{49}[/tex]

Answer:

C y=3.27x

Step-by-step explanation:

total cost = £3.27 times by the gallons

Step-by-step explanation:

B its B I had the same work and its B

Answer:

65-n

Step-by-step explanation:

"less than" means you will subtract the second number by the first, therefore 65 less than a number is 65-n.

Answer:

here you go I hope this is right

Answer:

jill age is 78 and tim's age is 87

Step-by-step explanation:

let jill age be x then, tim's age is 9+x

by the question,

2(9+x) + 2x = 330

or,18 + 2x + 2x = 330

or,4x = 330-18

or, x = 312÷4

x = 78

9+x= 9+78=87

1 millilitre = 0.001 litre

1 litre = 1000 millilitres

9 millilitres = 0.009

9 litres = 9000 millilitres

1,000 millilitres = 1 litre

1,000 litres = 1e+6

350 millilitres = 0.35 litres

350 litres = 350000 millilitres

Answer:

function

Step-by-step explanation:

I got that answer correct on ed2020

Answer:

Step-by-step explanation:

b/c this is an isosceles triangle  we know that either leg is the same length.. so we can use many trig functions  :)

SOH CAH TOA to remember how trig functions fit on the triangle...

we know the hypotenuse and the angle and we want to find the adjacent leg ( which for this triangle is also the opposite leg )

use Cos = Adj / Hyp

Hyp*Cos(45) = adj

16* [tex]\sqrt{2}/2[/tex] = adj

8*[tex]\sqrt{2}[/tex] = adj

each leg is the same  [tex]8\sqrt{2}[/tex]

Answer:

The length of the first piece is 0.51 m

The length of the second piece is 0.31 m

The length of the third piece is 0.28 m

Step-by-step explanation:

The question is a simultaneous equation with word problem

The total length of the wood = 0.9 m

The number of pieces the wood is cut into = 3

The length of the first piece = 0.2 m + The length of the second piece

The length of the third piece = The length of the second piece - 0.23 m

Let "y" represent the length of the second piece, let "x" represent the length of the first piece, and let "z" represent the length of the third piece, we have;

x = 0.2 + y...(1)

z = y - 0.23...(2)

x + y + z = 0.9...(3)

Therefore, by substitution, we have;

0.2 + y + y + y - 0.23 = 0.9

3·y - 0.03 = 0.9

3·y = 0.9 + 0.03 = 0.93

y = 0.93/3 = 0.31

y = 0.31

The length of the second piece = y = 0.31 m

From equation (1), we have;

x = 0.2 + y = 0.2 + 0.31 = 0.51

x = 0.51

The length of the first piece = x = 0.51 m

From equation (2), we have;

z = y - 0.23

z = 0.51 - 0.23 = 0.28

z = 0.28

The length of the third piece = z = 0.28 m.

Answer:

mark of the fifth exam = 60

Step-by-step explanation:

Mean = sum of all marks / number of exam

Mean = 70

Number of exam = 5

Let x =

Mean = sum of all marks / number of exam

70 = (65 + 80 + 76 + 69 + x) / 5

Cross product

70 × 5 = (290 + x)

350 = 290 + x

350 - 290 = x

x = 60

mark of the fifth exam = 60

Answer:

The measure confirming that PQRS would be 25

Step-by-step explanation:

It's easier if you draw it down.

1. We need to make this shape a parallelogram and the way we will do that is by making angle Q and angle S the same, because in parallelograms those opposite angles are required to be the same.  

                             \

                        155 \

P \ -------------------------\ Q

    \                         25 \

      \                               \     so that's your shape  

   S   \______________\ R

2.We were given that the exterior angle of Q measures 155, and since exterior and interior angles combined make 180, then we can assume that the interior angle of Q is 25.

3. As mentioned before, in a parallelogram, opposite angles are the same and  therefore PSR (which is just asking for the middle letter, S) is equal to 25 because Q is also 25.  

Answer:

D!

Step-by-step explanation:

Answer: Solved below...

Answer: Yes, that is a right triangle.

Step-by-step explanation:

To tell whether this is a right triangle or not you use a^2 + b^2= c^2

c is the hypotenuse the hypotenuse is the longest side of a right triangle, opposite the right angle. A and B can be either of the triangles sides.

To get this answer: 80^2+39^2 = 89^2

6400 + 1521 = 7921

7921=7921  

Since they are the same this IS a right triangle. Here is a little help for if the a question asks if you have a right acute or obtuse. To tell if you have an acute triangle the sign will be a greater than sign for ex) 180 > 169. If you have a obtuse triangle the sign would be a less than sign for ex) 120 < 200.

Here is a problem like that if you do not understand:

6^2 +12^2 = 13^2 ( remember c is the hypotenuse)

36+144= 169

180 > 169

Have a nice day!

Answer:

x = 11

Step-by-step explanation:

Here, we want to get the value of x

Let’s start by looking at the point U

Now, we can see angles on a straight line at that point

Mathematically, angles on a straight line are supplementary

What this mean is that they add up to 180

Now, the value of the angle that falls into the triangle on that straight line will be;

180-(11x + 12)

Now, we have all the angles of the triangle

Mathematically, the sum of all is 180 as the a sum of the angles of a triangle is 180

5x + 10 + 58 + 180-(11x+2 )= 180

5x + 10 + 58 -11x-2 = 0

-6x+ 66 = 0

6x = 66

x = 66/6

x = 11

Answer: 6

Step-by-step explanation:

Here's the complete question:

Olivia is making scarves. each scarf will have 5 rectangles, and 2/5 of the rectangles will be purple. how many purple rectangles does she need for 3 scarves.

Since each scarf have 5 rectangles, and 2/5 of the rectangles will be purple. The number of purple needed for each scarf will be:

= 2/5 × 5 = 2 purple

Therefore, the number of purple rectangles she need for 3 scarfs will be:

= 2 × 3

= 6

Answer:

The first angle is the smallest

Step-by-step explanation:

Step one:

given data

Angle 1= x+37

Angle 2= 90

angle 3= x+67

We know that the sum of angle in a triangle is 180

so

x+3+90+x+67= 180

collect like terms

2x+160= 180

2x=180-160

2x= 20

divide both sides by 2

x= 10

Step two:

so

Angle 1= 10+37= 47 °

Angle 2= 90= 90

angle 3= 10+67= 77 °

Answer:. The numbers are 41 and 14

Step-by-step explanation: X and Y represent the digits. In the Tens place, the digit has 10× its base value. Therefore we can set up equations to model the information given:

10x+y = 10y + x +27

X + Y = 5

y =5-x rewritten to substitute for y

10x + 5-x = 10(5-x)+x +27

Distribute and then combine like terms:

9x +5 = 50 - 9x +27

Add 9x to both sides; subtract 5 from both sides.

9x +9x = 50+27-5

18x = 72 Combine like terms. Then divide both sides to solve for x.

x = 4

4+y=5 Substitute 4 for x; solve for y.

y=1

Substitute values of x and Y into the original equation and check.

40 +1 = 10 +4 + 27

41 = 14+ 27

True! 41=41

The numbers are 41 and 14.

Answer: It's not possible to create 38 liters of green paint with whole liters of blue and yellow paint.

======================================================

Explanation:

The ratio of blue to yellow is 2:3. We have 2 parts blue and 3 parts yellow.

Multiply both parts by x to get 2x:3x

We have 2x parts of blue paint, and 3x parts of yellow paint.

x is some positive whole number.

In total, we have 2x+3x = 5x liters of paint. Set this equal to 38 and solve for x to get

5x = 38

x = 38/5

x = 7.6

We don't get a whole number, which contradicts how we set up x earlier. This must mean that Mark must use a fractional liters, instead of whole liters.

-------------------------

Here's another way to look at it:

Lets say he uses 2 liters of blue and 3 liters of yellow. This mixes to 2+3 = 5 liters of green.

Now let's say he uses 4 liters of blue and 6 of yellow. I multiplied both parts by 2. This mixes to 4+6 = 10 liters of green.

We continue this process to get the following

As you can see, we don't land on 38 liters of green. We can get to 35 liters or 40 liters, but not 38. Each of the amounts of green are a multiple of 5.

This is confirmation that Mark will have to use some fractional amount of liters of blue and yellow paint.

Answer:

60 degress

Step-by-step explanation:

How I got it:

1. Find out the angel of each side. 360 divded by 6 = 60

2. Get the answer of 60

Advice:

-Make an polygon using paper and rotate it. (Use protractor and ruler if your gonna do it)

Answer:

x = -0.22   or x = -2.28

Step-by-step explanation:

2x^2 + 5x + 1 = 0

You use the quadratic formula: -b ±√5² - 4 x 2 x 1 ÷ (2 x 2)

-5 +√17 ÷ 4 = -0.22

-5 - √17 ÷ 4 = -2.28

Answer:

10

Step-by-step explanation: