Pearson Algebra 2 Common Core, 2011
PA
Pearson Algebra 2 Common Core, 2011 View details
Cumulative Standards Review

Exercise 26 Page 494

Recall the formula a^2± 2ab+b^2=(a± b)^2.

- 4

Practice makes perfect

We want to solve the given equation by factoring. We will have to factor a perfect square trinomial. a^2± 2ab+b^2 ⇔ (a± b)^2

Factoring

Before we begin, let's rewrite the equation with all the non-zero terms on the left-hand side.
- 16 = x^2+8x
0=x^2+8x+16
x^2+8x+16=0
Since all the terms are on the left-hand side, we are ready to start factoring.
x^2+8x+16=0
(x+4)^2=0
(x+4)(x+4)=0

Solving

Now let's apply the Zero Product Property to solve.
(x+4)(x+4)=0
lcx+4=0 & (I) x+4=0 & (II)

(I), (II): LHS-4=RHS-4

lx_1=- 4 x_2=- 4
The only solution to this equation is x=- 4.

Checking Our Answer

Checking the answer
To check our answer, we will substitute - 4 for x in the given equation.
x^2+8x+16=0
( - 4)^2+8( - 4)+16? =0
â–Ľ
Simplify left-hand side
4^2+8(- 4)+16? =0
16+8(- 4)+16? =0
16-32+16? =0
0=0 âś“
Since substituting and simplifying resulted in a true statement, we know that x=- 4 is a solution of the equation.