SOLUTION: Systems of Equations and Inequalities Suppose you have a job at a restaurant that pays $12 per hour. You also work at a bookstore that pays $9 per hour. You want to earn a

Algebra.Com
Question 434346: Systems of Equations and Inequalities



Suppose you have a job at a restaurant that pays $12 per hour. You also work at a bookstore that pays $9 per hour. You want to earn at least $225 per week, but would like to work no more than 25 hours per week.
a. Write a system of linear inequalities that describes this situation.
b. Determine the solutions to the system. Explain what each solution to the system represents.

I was thinking that I need to have a problem equation something like this:
x+y=25
9x+12y=225
This is as far as I can get. Can you show me where I am going wrong and how to proceed.

Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
Suppose you have a job at a restaurant that pays $12 per hour.
You also work at a bookstore that pays $9 per hour.
You want to earn at least $225 per week, but would like to work no more than 25 hours per week.
:
a. Write a system of linear inequalities that describes this situation.
:
This is right, but should be written as an inequality
x + y =< 25
9x+12y=>225
:
Use the 1st equation for substitution in the 2nd equation
y = (25-x)
9x + 12(25-x) => 225
9x + 300 - 12x => 225
9x - 12x => 225 - 300
-3x => -75
Multiply by -1, to get rid of the negatives, this reverses the inequality sign
3x =< 75
x =<
x =< 25 hrs at the book store,
:
If you worked all 25 hr at the book store you would just make $225
Less than 25 hrs, you would work the remaining hr at the restaurant and make more than $225

RELATED QUESTIONS

suppose you have a job mowing lawns that pays $12 per hour. You also have a job at a... (answered by ikleyn,josgarithmetic)
The most you can work 25 hours in a week. Your babysitting job pays $12 per hour and... (answered by stanbon)
The most you can work 25 hours in a week. Your babysitting job pays $12 per hour and... (answered by Fombitz)
I am looking for the proper formula to complete this problem because I would like to try... (answered by stanbon)
You can work a total of no more than 37 hours per week at your 2 jobs. Housecleaning pays (answered by josgarithmetic)
I can work no more than 36 hours per week at my two jobs. Housecleaning pays $6 per hour, (answered by Theo)
I work at most 25 hours per week and earn at least $150 per week. I have two jobs, one... (answered by josgarithmetic)
This summer to earn extra money you decided to run a dog walking business in adddition to (answered by josmiceli)
You worked 14 hours last week and earned $96 before taxes. Your job as a lifeguard pays... (answered by likaaka)