Question 708675: At your grocery store, milk usually cost $3.60 per gallon. Ground beef cost $3 per pound. Today there are specials: milk is discounted $.50 per gallon, and ground beef is 20% off. Y you want to spend no more than $20. Write and graph a linear inequality to show how many gallons of milk and how many pounds of ground beef you can buy today.
Appreciate the help a lot :)
Answer by josgarithmetic(39617)   (Show Source):
You can put this solution on YOUR website! x and y, milk and beef quantities, in that order.
Prices today according to the discount: $3.10/gallon milk, 0.8(3)=$2.4/pound beef.
As a reminder, the units of milk is gallons and for beef is pounds.
Want to spend no more than $20 for this day.
More comfortable in slope-intercept form, but as long as that there is in standard, you can quickly find x and y intercepts. anyway,...
2.4y<=-3.1x+20
y<=-(3.1/2.4)x+20/2.4
Also, not if y=0, then x=6.45 "gallons" of milk. No buying more than 6 gallons & 1 quart of milk today, for practical purposes. Things change a bit if you are allowed to buy pints.
As example using this graph, you could buy 6 gallons of milk or less, and half a pound of beef or less, and that should cost less than or up to $20.
The region between the axes and the line are valid for "todays" discount prices.
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