Mica wants to rent ice skates. company a charges $15 for the skates and $1 for every hour skated. company b charges $12 for the skates and $2 for every hour skated.

1. Let cost of renting from company A by modeled by the function:
 
     A(h)=15+1*h , so 15 + 1 dollar times each hour scating
we can write it again in the standard form of a linear function as 

A(h)=h+15, similarly the cost of renting from company B is 
B(h)=2h+12

2. Draw the graphs of both lines. check the picture atached.

3. To draw A we can use 2 points : (0, A(0))=(0, 0+15)=(0, 15)
                                                        (1, A(1))=(1, 1+15)=(1, 16)

similarly with B

4. Lines A and B meet at the point h where A(h)=B(h)
so when 2h+12=h+15, h=3. 

5. As we can check from the graph, for the first 2 hours, the cost of renting from A is higher than renting from B. If Mica is going to skate for 3 hours, the cost is same. If she is going to skate for more than 3 hours, renting from A is cheaper.