Multiply x
and 3
Multiply x and 1
The x just gets copied along.
The answer is x
x
3*x evaluates to 3x
Because of the minus sign
3x becomes - 3x
The answer is -3x
Multiply y and 2
Multiply y and 1
The y just gets copied along.
The answer is y
y
2*y evaluates to 2y
-3*x-2*y evaluates to -3x-2y
The answer is -3x-2y-2
-3*x-2*y-2 evaluates to -3x-2y-2
so the first one is right
