What are the x-intercepts of ##y=x^2+2x-15##?

By setting it equal to zero,

##x^2+2x-15=0##

by factoring out,

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

by setting each factor equal to zero,

##{(x+5=0 Rightarrow x=-5),(x-3=0 Rightarrow x=3):}##

Hence, the ##x##-intercepts are: ##x=-5,3##.

I hope that this was helpful.