Question 1025366
 f(x) = x^2 + 4x - 12 Solve by completing the square. 
:
x^2 + 4x + __ = 12 
Complete the square, divide the coefficient of x by 2 and square it (4/2)^2
add to both sides
x^2 + 4x + 4 = 12 + 4
x^2 + 4x + 4 = 16
A perfect square which is:
(x+2)^2 = 16
Find the square root of both side
x + 2 = +/-{{{sqrt(16)}}}
x + 2 = +/- 4
Subtract 2 from both sides, two solutions
x = -2 + 4
x = 2
and 
x = -2 - 4
x = -6