Select the equivalent expression.(x−3⋅y3)−7=?
A.) x^21⋅y^-21
B.) (xy)^0
C.) x^−10⋅y^-4

I'm terrible at math any here is appreciated.

Negative 5 1/12 + negative 4 1/4 + 6 3/4

Which situation can be modeled by the inequality 5 + 10w ≥ 45? a. you start with $5 and save $10 a week until you have at least $45. b.you start with 5 baseball cards and purchase 10 cards every week until you have at most 45 cards. c.you start with 5 water bottles and purchases cases of 10 water bottles each until you have a total of 45 water bottles. d.you spend $5 plus $10 per week until you have less than $45.