Question

Solve 5x2 = –45x.

Answer 1

\[5x^2 = -45x ?\]
\[=> 5x = -45\]
\[=> x = -9\]

Answer 2

thanks!

Answer 3

No, you do not divide both sides by x. That is not the first step.

Answer 4

A Quadratic always has two solutions unless it is a perfect square.

Answer 5

\[
\\5x^2 = –45x
\\5x^2 + 45x = 0
\\5x(x + 9) = 0

\\5x = 0
\\x + 9 = 0

\\x = 0
\\x = -9
\]

Answer 6

The rule is "Never divide by the variable you are trying to solve for".