### Home > AC > Chapter 3 > Lesson 3.1.2 > Problem3-15

3-15.

Copy and simplify the following expressions by combining like terms.

1. $x+3x−3+2x^2+8−5x$

Flip subtraction to addition.

$x+3x+(−3)+2x^2+8+(−5x)$

Combine like terms.

Remember that you cannot combine $x$ and $x^2$.

$−x+2x^2+5$

1. $2x+4y^2−6y^2−9+1−x+3x$

See the hint in part (a).

1. $2x^2+30y−3y^2+4xy−14−x$

Remember that $xy$ cannot be combined with $x$ or $y$.

See the hints in part (a).

$2x^2+(−3y^2)+4xy+30y+(−x)+(−14)$

1. $20+3xy−3xy+y^2+10−y^2$

See the hints in part (a) and part (c).