Answer:
1) Plan A total cost = $85
Plan B total cost = $515
2) Plan A total cost = $85
Plan B total cost = $1030
Explanation:
given data
Plan A costs = $85
Plan B costs = $0.20 + $0.10 per text
sister use = 1,750 minutes and 1,650 texts
solution
we get here sister’s total cost under each of the two plans
Plan A total cost = $85
Plan B total cost = $0.20 × 1,750 minutes + $0.10 × 1,650 texts
Plan B total cost = $515
and
when sister doubles her monthly usage
Plan A total cost = $85
Plan B total cost = $0.20 × 3,500 minutes + $0.10 × 3,300 texts
Plan B total cost = $1030