Answer:
Step-by-step explanation:
I don't say you have to mark my ans as brainliest but if it has really helped you my friend don't forget to thank me...
Hello,
x = -5 or x = -3
x²+8x+15 = (x+4)² - 4² + 15 = (x+4)² - 1 = (x+4)² - 1² = (x+4+1) (x+4 -1)
= (x+5) (x+3)
x²+8x+15 = 0 ⇔ (x+5) (x+3) = 0
x+5 = 0 for x = -5
or x+3 = 0 for x = -3
