Chapter 4 - Exponential and Logarithmic Functions - Section 4.3 Exponential Functions - 4.3 Assess Your Understanding - Page 307: 77

$x=-4$

Use the power rule: $a^p=a^q$ . We can see that the base $a=e$ is the same on both sides of the equation. So, the exponents will also be equal. This implies that $p=q$ Therefore, $x=3x+8 \\ x-3x=8 \\ -2x=8 \\ x=-4$