Recall d = rt, distance = rate * time.
Answer:
c my aunt is a math teacher and told me the answer
a) Rainbow phone: c=100+6x
Cellular phone: c=80+10x
b) make the equations equal to each other:
100+6x=80+10x
20=4x
5=x
5 GB over
c)if x=6
Rainbow: 100+(6 x 6)= $136
Cellular: 80+(10 x 6)=$140
Therefore rainbow will save them the most money
