Question

Malene wrote the equation x² + 8x + 60 = x² + 12x + 20 to show that the area of a changed rectangle is 60 cm² greater than the area of the original rectangle. How did the rectangle change?

1 was added to each side.

2 was added to each side.

8 was added to each side.

10 was added to each side.

Answer 1

2 was added to each side.

Just took the test.

Answer 2

The answer is 10 was added to each side.

x² + 8x + 60 = x² + 12x + 20
____
Subtract x² from both sides:

x² + 8x + 60 - x² = x² + 12x + 20 - x²
8x + 60 = 12x + 20
60 - 20 = 12x - 8x
40 = 4x
x = 40/4
x = 10

So, 10 was added to each side.