quadratic formula

Solve the rational equation by combining expressions and isolating the variable y.

y=3x^2+9x−13

Hope this helps, whymenotsmart^m^.

$x = {-b \pm \sqrt{b^2-4ac} \over 2a}$      In you question  a = 3      b = 9    c = -13

$x = {-9 \pm \sqrt{9^2-4(3)( -13)} \over 2(3)}$

ops, i messed up again:( just can't beat EP (*sighs*)

thanks, Cal:)