Solve by using the quadratic formula

Question

x^2-4x-45=0

Answer 1

Look up the quadratic formula.
x = [-b +/-sqrt(b^2-4ac)]/2a
Then apply it. (a,b,c are the coefficients and constant in the equation)

You should get an integer solution since the equation can easily be foactored to give (x-9)(x+5) = 0
the solutions are 9 and -5.

Hint: b^2 - 4ac = 16 + 180 = 196, which had integer square roots + or - 14.