SOLUTION
Part A
From the question,
Green lawn charges $49 + $29 per month and
Grass team charges $25 + $37 per month
Let the number of month they will charge the same be x, then in x month, they both will charge
Solving for x, we have
Hence, they will cost the same in 3 months
Part B
The cost will be
Hence the answer is $136
Part C
If the family use the service for only 6 months, then
For Green Lawn, the cost would be
Hence, Green Lawn will cost $223
For Grass Team, the cost would be
Hence Grass Team will cost $247
Hence Green Lawn is a better option, since it is cheaper