Question

x2 - 4
Select one:
a. (x+4) (x- 1)
b. (x+2) (x+2)
c. (x-2) (x+2)
d. (x-2) (x-2)

Answer 1

Step-by-step explanation:

Theory : A difference of two perfect squares, A2 - B2 can be factored into (A+B) • (A-B)

Proof : (A+B) • (A-B) =

A2 - AB + BA - B2 =

A2 - AB + AB - B2 =

A2 - B2

Note : AB = BA is the commutative property of multiplication.

Note : - AB + AB equals zero and is therefore eliminated from the expression.

Check : 4 is the square of 2

Check : x2 is the square of x1

Factorization is : (x + 2) • (x - 2)

Equation at the end of step

1

:

(x + 2) • (x - 2) = 0

STEP

2

:

Theory - Roots of a product

2.1 A product of several terms equals zero.

When a product of two or more terms equals zero, then at least one of the terms must be zero.

We shall now solve each term = 0 separately

In other words, we are going to solve as many equations as there are terms in the product

Any solution of term = 0 solves product = 0 as well.