x^2+8x+15=0 Use any method

Question

The answer is -3,-5 But i am having trouble getting that please show me steps thank you

Answer 1

X^2 + 8X +15 =0

 

( X + a ) ( X +b ) =0

 

  a, b should be such that   a+b=8   ab = 15     and a = 5   b=3  is the answer.

Answer 2

x^2+8x+15=0

factor x^2+8x+15

5*3=15 and 5+3=8

(x+5)(x+3)=0

set each factor equal to 0

x+5=0

x=-5

x+3=0

x=-3