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

3-15.

Copy and simplify the following expressions by combining like terms.

1. $x+3x−3+2x^2+8−5x$

$x+3x+(−3)+2x^2+8+(−5x)$

Combine like terms.

Remember you cannot combine $x$ and $x^2$.
Also remember to put the terms in decreasing order of their exponents.

$2x^2−x+5$

1. $2x+4y^2−6y^2−9+1−x+3x$

See the hints in part (a).

$−2y^2+4x−8$

1. $2x^2+30y−3y^2+4xy−14−x$

See the hints in part (a).

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

$2x^2−3y^2+4xy+30y−x−14$

1. $20+3xy−3xy+y^2+10−y^2$

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

$30$