Could anyone help me to slove these problems.

1. (x/(x^2-100))9x(x+10)/(x+3))

2. (x/x^2-100))/(9x(x+10)/(9x(x+10)/(x+3))

3. What is the least common multiple of the expressions: 2x,x^3,(x+1),(x+1)^2,(x-9)

4.(2y/x^2)+(7/x(x-3))

5.(2y/x^2)-(7/x(x-3))