Absolute Value

Solving Equations

Solve Ix - 4I + 1 = 9.

Step 1. Isolate the absolute value bars using inverse operations.

Ix - 4I + 1 - 1 = 9 - 1

Ix - 4I = 8

Step 2. Write two equations.
a. Write one equation to equal the positive.
b. Write the other equation to equal the negative.
c. Solve for x.

x - 4 = 8 and x - 4 = -8

x - 4 + 4 = 8 + 4 and x - 4 + 4 = -8 + 4

x = 12 and x = -4

Step 3. Check the solutions.