simplify: {[3x^2+10x-8]/[5x-15]}/{[x^3+64]/[x^2-9]}

Rewrite the following terms:

5x-15 = 5(x-3)
x^2-9 = (x+3)(x-3)
3x^2 + 10x -8 = (x+4)(3x-2)
x^3 +64 = (x+4)(x^2 -4x +16)
Then cancel factors than appear in both numerator and denominator.