Tara has a large box of dog treats that weighs 7.8 pounds. She uses the large box of dog treats to make smaller bags, each containing 0.6 pound of treats.

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.

i believe it is c.y = 9x

rise over run. 9 units up over 1 unit right or 9/1