Question

What the answer to this problem

Answer 1

5n=30+3n You need to exclude the 4 due to for the first 4GB cost $30 then $3 for each additional GB used

Answer 2

The bottom right hand corner.
5n=30+3(n-4)
5n=30+3n-12
5n=18+3n
2n=18
N=9
Plan A will charge $45. 9x5=45
Plan B will also charge $45 because
(9-4)x3+30=45