Using the axioms for Z, prove the following. Each step must be justified by an axiom or by replacement. a. (a, b,c EZ). (1 + a)(c +b) = (c+b)a + (b + c)
b. (Vx, y e Z). 20 Ay+0= ry 0.

Fanny mendelssohn manages all the magazines and paperback books at a local grocery store. she prices many paperbacks to sell at $7.99. the cost to the store is $5.29. what is the markup rate on a paperback book, based on its cost?

What are the domain and range of the function f(x)=2^x+1

Aremote-controlled boat can travel at 4 feet per second in calm water. the boat traveled 48 feet with the current, and then it traveled 16 feet against the current in the same amount of time. how fast is the current?