SOLUTION: Help me with this word problem please? "Your mother now takes a 4 loads of laundry each week to a laundromat where each load costs $1.25 to wash. To save family money, she wants to

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Help me with this word problem please? "Your mother now takes a 4 loads of laundry each week to a laundromat where each load costs $1.25 to wash. To save family money, she wants to      Log On


   

Question 822505: Help me with this word problem please? "Your mother now takes a 4 loads of laundry each week to a laundromat where each load costs $1.25 to wash. To save family money, she wants to buy a washing machine for your home that costs $400. The electricity to operate the machine for 4 loads will cost $1 per week. How many loads of laundry must your mother wash before buying the washing machine that actually saves the family money?" The more detail the better! Thanks :)
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
Find the cost of washing without the home machine, the cost for buying and using the home machine, and compare. For how many loads done with the home machine will the costs be equal? The variable is how many weeks of laundry, at 4 loads per week.. Call this s for weeks of laundry.

Without home machine: 4%2A1.25%2As where s is number of weeks.

With home machine: 400%2B0%2B1%2As

You want to know for how many weeks (at 4 loads of wash per week) will home machine become less cost than taking the laundry loads to a laundromat.
highlight%28400%2Bs%3C4%2A1.25%2As%29
400%3C4%2A1.25s-s
400%3C%284%2A1.25-1%29s
400%3C4s
highlight%28s%3E100%29
'
Knowing that mother does 4 load per week nomatter what washing arrangement, 100 weeks means 400 wash loads. She needs to do more than 400 wash loads at four loads per week before she begins to save money with the new home washing machine.