Solve 3x^2+7x-13=7 to find x.

Firstly, you need to get the equation to equal zero, so that you can use the quadratic formula to solve. Therefore you subtract 7 from both sides, meaning the equation becomes: 3x^2+7x-20=0. Recall the quadratic formula: x =( -b +/- sqr root(b^2-4ac))/2a, when the equation is ax^2+bx+c, this means that a = 3, b = 7 and c = -20. Subbing this into the formula you get that x = -4 and x = 1.67 (to 2 dp).