Chapter 5 - Exponential and Logarithmic Functions - 5.6 Logarithmic and Exponential Equations - 5.6 Assess Your Understanding - Page 311: 20

$\frac{15}{4}=3.75$

Step 1. Rewrite the equation as $log(2x)=log10+log(x-3)$ Step 2. Thus $2x=10(x-3)\longrightarrow 2x=10x-30\longrightarrow 8x=30\longrightarrow x=\frac{15}{4}$. Step 3. Check answers, $x=\frac{15}{4}=3.75$ fits the original equation.