How do you solve x^2 -3x = -7 using the quadratic formula?

1 Answer
Jul 20, 2015

x=(3+sqrt(19)i)/2, (3-sqrt(19)i)/2

Explanation:

x^2-3x=-7

Get all terms on the left side.

x^2-3x+7=0 is a quadratic equation in the form ax^2+bx+c=0, where a=1, b=-3, and c=7.

Quadratic Equation

x=(-b+-sqrt(b^2-4ac))/(2a)

Substitute known values into the formula.

x=(-(-3)+-sqrt(-3^2-4*1*7))/(2*1) =

x=(3+-sqrt(9-28))/2

x=(3+-sqrt(-19))/2

x=(3+-sqrt(19)i)/2

Solve for x.

x=(3+sqrt(19)i)/2

x=(3-sqrt(19)i)/2