Question

What is the missing constant term in the perfect square that starts with x^2 - 20x

Answer 1

(a - b)² = a² - 2ab + b²

- 2ab = 20x

- ab = 10x } => b = - 10

a = x

(x - 10)² = x² - 20x + 100

Answer 2

100

Explanation:

To make a perfect square trinomial, you want to divide the use the following equation to find the missing constant:

`((b)/(2) )^(2)` when the quadratic is in standard form.

In this case, we would divide -20 by 2 and square it

-20/2 = -10

(-10)^2 = 100