Can someone explain the properties and me with this work?

The first property is commutative  ( the numbers 38 and 677 are  swapped over)

Then we have the associative property ( where the paretheses are moved to get 38 and -38 together)

then the additive inverse ( 38 + (-38) = 0

and finally to get the 677 we use the additive identity property.

There is no graph but what i can say is that 1 is the slope and that -2 is the y- intercept