7z-2[3(x-2y)-4{2z-(2y-3y-3x-5z)}]

1 answer

I assume you want to simplify.

Get rid of internal parentheses first, remembering that a negative times a positive is a negative and a negative times a negative is a positive.

7z-2[3(x-2y)-4{2z-(2y-3y-3x-5z)}] =

7z-2[3x-6y-4(2z-2y+3y+3x+5z)] =

7z-2(3x-6y-8z+8y-12y-12x+20z) =

7z-6x+12y+16z-16y+24y+24x-40z =

Combine like terms.