Answer: {6, 3}
Step-by-step explanation: This is called a polynomial equation.
In order to solve a polynomial equation by factoring,
it's very important to understand the following rule.
Before we can factor, we must set the equation equal to zero.
Our first step is to move the 9x to the left so it's set equal to zero
by subtracting 9x from both sides to get x² - 9x + 18 = 0.
Now we can factor the left side to get (x - 6)(x - 3) = 0.
This means that either x - 6 = 0 or x - 3 = 0.
Solving each equation from here, we have x = 6 or x = 3.
In set notation we have {6, 3}.