Answer:
x = approx. 1.24 or -7.24
Step-by-step explanation:
It's hard to factor directly so we should use the quadratic formula or complete the square. I'm going to go with completing the square.
x²+6x-9=0
x²+6x=9
x²+6x is the same as x²+2·3·x, in order to make this into the algebraic identity (A+B)²=A²+2AB+B², we must add B², or in this case 3² to both sides. (A is x, B is 3)
x²+6x+9=18
(x+3)²= 18
x+3= ±√18
x= ±4.24 -3 (approximately 4.24)
First solution for x = 4.24-3 = 1.24
Second solution for x = -4.24-3 = -7.24
