### Home > CCA > Chapter 3 > Lesson 3.1.2 > Problem3-21

3-21.

Simplify and solve each equation below for $x$. Record your work.

Use the CPM algebra tiles application.

1. $3x−7=2$

• Add $7$ to both sides.

$3x−7=2$
$\ \ \ \ +7\ +7$

$3x=9$

Divide both sides by $3$.

$\frac{3x}{3}=\frac{9}{3}$

$x=3$

1. $1+2x−x=x−5+x$

• Combine like terms.
$x+1=2x−5$

Move $x$ to one side by subtracting $x$ from both sides.

$x+1=2x−5$
$−x\ \ \ −x$

$1=x−5$

Isolate $x$ by adding $5$ to both sides.

$x−5=1$
$+5\ \ \ \ +5$

$x=6$

1. $3−2x=2x−5$

• Refer to parts (a) and (b).
1. $3+2x−(x+1)=3x−6$