When we solve a linear equation in one variable such as: x + a = c, we need to use two properties. The first is known as the additive inverse property. The second is known as the addition property of equality. We will use these properties together to gain a solution to our equation.

Test Objectives
• Demonstrate an understanding of the additive inverse property
• Demonstrate the ability to use the addition property of equality to solve an equation
• Demonstrate the ability to check the proposed solution for an equation
Addition Property of Equality Practice Test:

#1:

Instructions: solve each equation.

$$a)\hspace{.2em}x + 10=12$$

$$b)\hspace{.2em}x - 5=-3$$

#2:

Instructions: solve each equation.

$$a)\hspace{.2em}x + 1=9$$

$$b)\hspace{.2em}x - 1=-7$$

#3:

Instructions: solve each equation.

$$a)\hspace{.2em}x + 3=14$$

$$b)\hspace{.2em}3x - 10=2x - 5$$

#4:

Instructions: solve each equation.

$$a)\hspace{.2em}2x + 9=x - 3$$

$$b)\hspace{.2em}5x + 4=4x - 7$$

#5:

Instructions: solve each equation.

$$a)\hspace{.2em}2x - 11=3x + 6$$

$$b)\hspace{.2em}9x + 1=8x - 13$$

Written Solutions:

#1:

Solutions:

$$a)\hspace{.2em}x=2$$

$$b)\hspace{.2em}x=2$$

#2:

Solutions:

$$a)\hspace{.2em}x=8$$

$$b)\hspace{.2em}x=-6$$

#3:

Solutions:

$$a)\hspace{.2em}x=11$$

$$b)\hspace{.2em}x=5$$

#4:

Solutions:

$$a)\hspace{.2em}x=-12$$

$$b)\hspace{.2em}x=-11$$

#5:

Solutions:

$$a)\hspace{.2em}x=-17$$

$$b)\hspace{.2em}x=-14$$