Before we get started on this question. It doesn't belong in The Advanced algebra section.(alot of folks wont look here). Try using Algebra or urgent help for a faster responce.
Since we are not allowed to divide by zero, we want to find all values of x that would make the denominator zero.
since the b term (the middle one) is negative and the c term (the constant) is positive both factors must be negative.
so we need factors of 15 that add up to -8
the factors of 15 are 1,15 and 3,5
since 3+5=8 this is what we want so we get...
setting each factor equal to zero and solving we get x=3 and x=5
I hope this helps.