Hi guys, i have a couple question from my homework i am having trouble with a little more then a couple , if any one could help i would appreciate it.

1) Simplify or combine where possible, sin(x + x) = i get 2sinx (Answer is sin2x) why is the 2 there? not in front?

2) 5sinxsinx = i get 5sinx^2 (answer is 5sin^2x)

Thanks in advance.