Answer
a. Yes
b. No, you can still distribute the negative sign outside of the parenthesis
c. No, the variables 12xy and -3yx can still be simplified because they both have the same coefficients, x and y
Work Step by Step
a. $4xy^{3} + 5x^{3}y$ are simplified completely because the two are not like terms
b. -(y-1) still has a negative sign that can be distributed
c. 12xy and -3yx are like terms despite the fact that the order of coefficients is different. By the rules of multiplication, 12xy=12yx and -3xy=-3yx
