Which of the following are useful ways of finding the value of a variable? check all that apply

a. writing an equation
b. drawing a graph
c. reading a table
d. drawing a diagram

F(x) = 1/x g(x)=x-4 can you evaluate (g*f)(0) ? why or why not?

Acomputer store buys a computer system at a cost of $370.80. the selling price was first at $ 618, but then the store advertised a 20 % markdown on the system. answer parts a and b. a. find the current sale price.

Harold wrote this equation to model the level of water in a pool over time. the variable x represents time in hours. f(x) = 3,500 - 225x which statements about the situation are true? check all that apply. the water level is rising. the water level is falling. the initial level of water in the pool was 3,500 units. the initial level of water in the pool was 225 units. the pool was empty after 14 hours. the water was 2,600 units high after 4 hours.