Question

What number should be added to the expression x2 14x to change it into a perfect square trinomial?.

Answer 1

49

Explanation:

When you look at the square of a binomial, you see ...

(x +a)^2 = x^2 +(2a)x +a^2

The constant value (a^2) is the square of half the x-coefficient.

(14/2)^2 = 49 . . . . the value to be added.

Adding 49 gives ...

x^2 +14x +49 = (x +7)^2