Question 451619
x^2 + 4x - 36 = 0
x^2 + 4x = 36
half 'b' and square it -- then add to both sides
x^2 + 4x + 4 = 36 + 4
(x+2)(x+2) = 40
(x+2)^2 = 40
x+2 = sqrt(40)
x+2 = sqrt(2*2*2*5)
x+2 = 2*sqrt(2*5)
x+2 = 2*sqrt(10)
x = 2*sqrt(10) - 2
x = 4.325