Question

Factor completely. 640-10x^2

Answer 1

10 ( 8-x)(8+x)

Explanation:

640-10x^2

Factor out 10

10( 64-x^2)

This is the difference of squares

(a^2 - b^2) = (a-b)(a+b)

Rewriting

10 ( 8^2-x^2)

10 ( 8-x)(8+x)

Answer 2

10(8 - x)(8 + x)

Explanation:

Given

640 - 10x^2

Solution

Take out 10 on each side of the minus sign

10(64 - x^2)

The expression in the brackets is a difference of squares which factors as

a^2 - b^2 = (a + b)(a - b)

Factor the expression inside the brackets as a difference of squares.

64 = 8*8

x^2 = x*x

10(8 - x)(8 + x)