1)simplify root 5xy^5* root 10x^3
2) If f(2)=0 and f(x)=3x^2+kx-4, find k
3) if g(x)=3x^2+2x+6 and f(x)=4x-5, find g(2)/f(5)
4)if h(x)=13-5x,find h(x+5)