yeah, i know, im stuck again.

thankyou!!

Factorise using the method of completing the square:

x^2 + 5x - 11

You can solve this problem by using the quadratic formula, but since you need to do it by completing the square I'll show you how to do it that way.

x^2 + 5x -11 = 0

a = x^2, b = 5x, and c = -11

1) add c to the other side

x^2 + 5x = 11

2) multiply b by 1/2 and then take the square root

[5(1/2)] = (5/2)^2 = 25/4 = b

3) add b to both sides

x^2 + 5x + 25/4 = 11 + 25/4

4) factor the left side and add the right side

(x + 5/2)^2 = 69/4

5) take the square root of both sides and simplify

x + 5/2 = +/-sqrt(69/4)

x + 5/2 = +/- sqrt(69)/2

6) subtract 5/2 on both sides

x = -5/2 +/- sqrt(69)/2

x = (-5 +/- sqrt(69))/2