it says simplify each expression. justify each step.

Question

1. (2 + 7m) + 5
2. 9 x (r x 21)

Answer 1

1. Why not add the 5 and the 2?

2. Does the x indicate multiplication, or a variable?
I will assume it is a variable. It is better to use * instead of x when typing, for multiplication to avoid confusion.
9 x (r x 21) = (9*21)x^2*r
Multiply out the 9*21.

Answer 2

a+(b+2)=(b+12)+a