CPM Homework Help : PC3 Problem 4-8

Recall that not all equations have real solutions. Sometimes the solutions to equations are complex numbers. Use the Quadratic Formula to solve the following equation. Hint: $i^2=-1$

$−13=x^2-4x$

Hint:

$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

More Help:

$\sqrt{-9}=3i$

Step:

Add $13$ to both sides of the equation so that the quadratic expression is equal to $0$ and the Quadratic Formula can be used.