## Thinking Mathematically (6th Edition)

5x+3 = 18 Step 1: Subtract 3 from both the sides 5x+3 - 3 = 18 -3 Step 2: Simplify 5x = 15 Step 3: Divide both the sides by 5 $\frac{5x}{5}$ = $\frac{15}{5}$ Step 4: Simplify x = 3 Now we check the proposed solution, 3, by replacing x with 3 in the original equation. Step 1: the original equation 5x+3 = 18 Step2: Substitute 3 for x 5.3 + 3 = 18 Step 3: Multiply 5.3 = 15 15 + 3 = 18 Step 4: Add 15+3 = 18 18 = 18 Since the check results in true statement, we conclude that the solution set of the given equation is {3}