Factor 2x²−x−10 . Rewrite the trinomial with the x-term expanded, using the two factors. Then, group the first two and last two terms together and find the GCF of each.

Answer 1

2x²-x-10 You look for separating the trinomial into to binomials ()() using FOIL backwards. FOIL stands for First, Inside, Outside, Last terms. First- 2x² is the first term in each binomial only one way to do this:

(2x )(x ). Now, look at the Last terms-10 Several ways: 2 x -5 or 5 x -2 or 10 x -1, or 1 x -10, -2 x 5, or -5 x 2. Which set will give me the middle term when I FOIL them together?

You just try different combos until you get there- you will get good at this after practice!

(2x - 5)(x+2) = 2x²- 5x +4x-10 =2x²-1x-10

Now it asks you to use grouping with the 4 terms

2x²- 5x +4x-10= (2x²- 5x) +(4x-10) We group the first two terms and the last two terms.

(2x²- 5x) +(4x-10) Find a GCF - Ok for the first group x is common so we have x(2x-5),and for

(4x-10)=2(2x-5), the second grouping GCF. both groups have in common (2x-5).We factor this whole part out 2(2x-5)+x(2x-5) = (2x-5)(2+x)=(2x-5)(x+2)

Answer 2

2x^2 -x - 10 = (2x-5)(x+2) = 2x^2 + 4x -10

= 2x^2 -5x + 4x -10

=(2x^2 + 4x) - (5x +10)

= 2x(x+2) - 5(x+2) factor out x+2

= (2x-5)(x+2)