# Expanding and Simplifying Two Sets of Double Brackets (most likely really easy)

## Homework Statement

Expand and Simplify 6(x-1)(x+2)-(1-x)(2+x)

## Homework Equations

The answer in the book is 7x^2+7x-14

## The Attempt at a Solution

I've tried several ways, but all of them give the wrong answer.
I'm not sure what to do with the negative in the middle. I know it makes everything in the bracket the opposite sign (i.e. - becomes +, + becomes -) but is that for both (1-x) AND (2+x), or just (1-x)?
I'm also not sure whether to multiply the (x+2) by 6 as well as the (1-x).

first I expanded to get 6x-6+x^2-x+2x-2-2-x+2x_x^2, which simplified to 2x^2+14x+4
then I tried expanding again, without multiplying the (x+2) by 6, and got 6x-6+x^2-x+2x-2-2-x+2x+x^2 = 2x^2+6x+2

I know this is really easy, it's my first piece of maths homework for the year, but I've spent two hours trying different ways to do this problem.

Related Precalculus Mathematics Homework Help News on Phys.org
Try this,
6(x-1)(x+2)-(1-x)(2+x)

=6(x-1)(x+2)+(-1)(1-x)(2+x)[-(1-x)(2+x) means (-1)(1-x)(2+x)]

= 6(x-1)(x+2)+(x-1)(2+x)[here i multiply -1 to (x-1) only ]

let (x-1)(x+2) be a [ just for simplicity]
then we have,

=6a+a

=7a
now a=(x-1)(x+2) =(x2+ 2x -1x -2)= (x2+1x-2)

=7(x2+1x-2)
=7x2+7x-14

I hope it helps!

Thank you so much! 