X2+2x-15=0 factorising

x²+2x-15 = (x-3) (x+5)

Step-by-step explanation:

hello:

x²+2x-15=0

(x²+2x+1) - 1-15=0

(x+1) ²-16=0

(x+1) ²-4² = (x+1-4) (x+1+4) use identity : a²-b² = (a-b) (a+b)

x²+2x-15 = (x-3) (x+5)

(x-3) (x+5)

Step-by-step explanation:

x²+2x-15 find two numbers that add to make + 2 and make a product of - 15

-3*5=-15

-3+5=2

(x-3) (x+5)