



 
Hi Ashley, To use the quadratic formula you need the the quadratic equation in the form $a x^2 + b x + c = 0.$ To obtain this from your equation first expand both sides to get \[x(x3) = 5 (x+4) = x^2  3x = 5x + 20\] and then subtract $5x + 20$ from both sides and simplify. Now you should be able to use the quadratic formula. Penny  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 