What number must you add to complete the square? x2 + 12x = 40

36 should be added to make the left side a perfect square.

Step-by-step explanation:

We know that

If we compare the first two terms of the left side with , we get,

a = x,

2ab = 12x

But since a = x,

2xb = 12x

Cancel x both sides and divide both sides by 2.

b = 6

So, should be added to the left side to make it a perfect square.

$9.89

step-by-step explanation:

9.90 = p x .06 x .25 (3/12 changed to a decimal)

9.90 = p x 0.015

9.90 - 0.015 = p

9.89 = p