Is this true or false?

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (-1+i)+(21+5i)+0

F(x)=5/6x+3 which of the following is true

What is the slope of the line passing through the points (3, 3) and (5, 7) ? 1. 2 2. 1/2 3. −2 4. −1/2