Question

How do you solve `3x^2 = -9x` by factoring?

Answer 1

The answer is:
`x = 0` or `x = - 3`

Explanation:

Let's do this in steps

First, move all instances of "x" to one side of the equation.
`3x^2 = - 9x`
`3x^2 + 9x = 0`

Next, factor out common coefficients 3.
`(3) (x^2 + 3x) = 0`

By factoring (as you requested), factor out x from the parentheses.
`(3x) (x + 3) = 0`

At this step, you will be able to find both answers (as this is a quadratic equation).
When `(3x) = 0`,
`x = 0/3` -> Divide both sides by 3 to get x on the left
`x = 0`
When `(x + 3) = 0`
`x = - 3` -> Minus both sides by 3 to get x on the left