Yes. Let's look at PEMDAS. Parentheses, Exponents, Multiplication, Addition, Subtraction. As we can see, multiplication comes first. In -2 + 3x, reading it from left to right, we see the addition symbol first, but because we're supposed to do multiplication, we have to do the 3x first. The same goes for 3x + (-2).
Yes. The two expressions -2 + 3x and 3x + (-2) are equivalent.
Hope this explanation helped you out. :)
