Question

Solve the quadratic equation y2 - 7y - 18 = 0 by factoring.

Answer 1

Alright, so what when multiplied gives you 18 but when added gives you 7?
Hint: one number will need to be negative.

Answer 2

\[\LARGE{\color{green}{y^2-7y-18=0}}\]\[\Large{\color{blue}{\implies y^2-9y+2y-18=0}}\]\[\Large{\color{blue}{\implies y(y-9)+2(y-9)}}\]\[\Large{\color{blue}{\implies (y+2)(y-9)}}\]

Answer 3

\[\Huge{\color{orange}{y=-2}}\]\[\Huge{\color{orange}{y=9}}\]