Question

Which expression is the result of the perimeter of rectangle B minus the perimeter of rectangle A?

The following table shows the length and width of two rectangles:


Length Width
Rectangle A x + 8 x − 1
Rectangle B 4x + 5 3x − 2


Which expression is the result of the perimeter of rectangle B minus the perimeter of rectangle A?
10x − 12
18x + 32
10x − 8
18x + 6

Answer 1

the other person was correct. 10x - 8.

Answer 2

10x - 8

Explanation:

The perimeter of these can be found by adding length and width and then multiplying by two.

Rectangle A: (with all of the variables already doubled)

2x + 16 + 2x - 2

2x + 2x + 16 - 2

4x + 14

So rectangle A's perimeter is 4x + 14.

Rectangle B: (Still with all the variables already doubled)

8x + 10 + 6x - 4

8x + 6x + 10 - 4

14x + 6

So rectangle B's perimeter is 14x + 6

And now to subtract the two.

(7x + 3) - (4x + 14)

14x + 6 - 4x - 14

14x - 4x + 6 - 14