I wonder why my answer was deleted. it was correct.
so if we wanted to cancel the terms, we would try to get the smaller term to be a negative form of the bigger one
we have the terms
a and b and
4a and 2b
to cancel the b's we would have to multiply b by -2
to cancel the a's we would have to multiply the a's by -4
to keep the truth of the sentence, we have to do that to the whole equation
so we see that there is no multiplying by -2 but there is multiplying by -4 so that is the answer
the one that is : -4(a+b=6) is the answer