Question

What two methods are the best choices to factor this expression?

18x2-8

-Factor by grouping.

-Factor out the GCF.

-Use the difference of squares rule.

-Use the perfect square trinomial rule.

Answer 1

Factor out the GCF, and Use the difference of squares rule.

Explanation:

The terms in the expression have a common factor of 2, so the first step is to factor out the GCF:

2(9x2 − 4).

Then, factor the remaining expression using the difference of squares rule.

Answer 2

- Factor by grouping.

- Factor out the GCF.

Explanation:

Given the expression 18x²-8, the best method to factor this expression are Factor by grouping and by factoring out the greatest common factor.

Step 1: Factor by grouping

Factor by grouping is done by creating a smaller groups from each term in the expression as shown;

18x² = (2*3*3* x²)

8 = 2*2*2

18x²-8 = (2*3*3* x²) - (2*2*2)

Step 2: Then we will factor out the greatest common factor (GCF) in the expression. GCF is the value that is common to both terms of the expression. The only common term in this case is 2.