I'm having a real problem solving x^2-4x-5=0 using the sq method. Can anyone help me?
+33653 I think you probably mean the "completing the square" method.
Add the square of half the coefficient of the x term to both sides:
x^2 - 4x + (-4/2)^2 - 5 = (-4/2)^2
simplify; x^2 - 4x + 4 - 5 = 4
Add 5 to both sides: x^2 - 4x + 4 = 9
The left-hand side can now be expressed as a perfect square:
(x - 2)^2 = 9
Take square root of both sides:
x - 2 = 3 and x - 2 = -3
So: x = 5 and x = -1
.
