$$3\left(z-y\right)^2-4y^3$$  Evaluate the expression when y = 2 and z = 4.

$$3a^2+2b\ -4b^3\$$  Ο $$2a^2b^2$$  Evaluate and compare these two expressions when a = 4 and b = 3

A cell phone company a $20 monthly fee and then 45 cents per minute. The company uses the expression 20 + 0.45m to find how much to charge for each month. How much would the company charge for 200 minutes?