Question

Can someone explain how this works?

Answer 1

Explanation:

2n² - 6n -8

step1: multiply 2 by -8

2 × -8 = -16

step 2: find factors of -16

-16 = { 1, 2, 4, 8, 16}. or {-1, -2, -4, -8, -16}

step 3: focus on -6 as in the equation 2n² - 6n -8

Step 4: pick from the factors, any two numbers when added will result in -6.

factors -8 and 2 now represent -6n

why; -8 + 2 = -6

step 4: rewrite equation as

2n² -8n +2n -8

Step 5: factorize

2n ( n - 4) + 2( n -4)

(2n +2) ( n -4)

Answer 2

Explanation:

The expression on the top is a quadratic polynomial equation. The bottom expression is the "factored out" version of the top expression. They are equal to each other. If you multiply the bottom expression using FOIL (first, outer, inner, last) you get:

(n + -4)(2n + 2) = 2n² - 8n + 2n - 8 = 2n² - 6n - 8, which is the top equation