Question

The length of a rectangle is 7 inches more than its width. The perimeter of

this rectangle is 78 inches. Find the length of this rectangle.

Answer 1

Explanation:

Let the length = 7x

Let the breadth = x

As we know that

perimeter of rectangle =2(l+b)

Also perimeter here = 78 inches

Acc. to question

2(l+b) = 78 inches

`2(7x + x) = 78`

`16x = 78`

`x = (78)/(16)`

`x = 4.8`

so bredth = 4.8 approx

length = 7*4.5 =31.5 approx

Hope it helps u

Answer 2

First known equation is:

2L + 2W = 46

Second equation is:

L = W +7

Put the variable L of the second equation in the first equation.

2(W+7) + 2W = 46

2W +14 +2W = 46

4W = 32

W=8

Then resolve L using any of the above initial equations

L = 8 + 7 = 15

Verify: 2L +2W = 46

2(15) + 2(8) = 30 + 16 = 46 = perimeter