alex earned $20. he earned 1/4 of the amount rob earned. how much did rob earn? write an equation to match.

Can you guys please do both with the work please and thank you if you actually do it

salantis [7]

Answer:

7. 29 cm

8. equation: 61 = (x) +(2x -7) +(3x +2); sides 11, 15, 35

Step-by-step explanation:

7. Let w represent the width. The length is 3 less than twice the width, so the length is 2w-3. The perimeter is given by the formula ...

P = 2(L+W)

Substituting the known values, we have ...

90 = 2((2w-3) +w)

45 = 3w -3 . . . . . . . . divide by 2

15 = w - 1 . . . . . . . . . .divide by 3

16 = w . . . . . . . . . . . . add 1

L = 2w -3 = 2(16) -3 = 29

The length of the rectangle is 29 cm.

__

8. The equation that should be used is the one that relates the side lengths to the perimeter.

P = a + b + c . . . . for sides a, b, c

61 = (x) +(2x -7) +(3x +2)

61 = 6x -5 . . . . . . collect terms

66 = 6x . . . . . . . . add 5

11 = x . . . . . . . . . . divide by 6

Then the side lengths are ...

a = x = 11

b = 2x -7 = 2(11) -7 = 15

c = 3x +2 = 3(11) +2 = 35

_____

Comment on problem 8

You will notice that the side lengths do not satisfy the triangle inequality: the sum of the short sides is not greater than the long side. These side lengths cannot form a triangle. Cute algebra, but bad geometry.

4 0

3 years ago

For the Rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. For an 10 month period

Svetllana [295]

For a 10 month period the last term is 10 and the series sum is 55. For a 15 month period the last term is 15 and the sum is 120. For a 20 month period the last term is 20.
If u want the sum then it is 210.

Hope this helps you!

5 0

3 years ago

HELPP PLEASE

Aleksandr [31]

152.6315 is because If you dived 870 by 5.7 it will be that.

6 0

2 years ago

Read 2 more answers

From a piece of paper, Sam cuts a rectangle with a length that is 2 inches (in.) longer than the width. He tapes a straw to the

Ksivusya [100]

Answer:

c)A cylinder with a volume of π(w³ +2w² )in³

where w represents the width of the cylinder.

Step-by-step explanation:

A cylinder with a volume of π(w³ +2w² )in³

where w represents the width of the cylinder.

The volume of a cylinder is given by V=Bh or V=πr²h

where B is the area of the base and h is the height of the cylinder.

V=πr²h-------equation1

V= π(w³ +2w² )--------- equation2

Comparing equation 1 and equation 2

πr²h=π(w³ +2w² )

r²h=(w³ +2w² )

r²h= w²(w +2 )

Taking w² common leaves w+2 which gives the height or length of the cylinder.

Therefore radius = width and height = length which gives the volume of the cylinder.

8 0

3 years ago

Which expression shows a sum of three terms? (1 point)

Elina [12.6K]

The last expression shows the sum of three terms. The sum is the amount resulting in addition.

The answer is x + 3 + x

4 0

2 years ago

Read 2 more answers