SOLUTION: Hi appreciated tutors,
I have been studying linear systems and have a good understanding of solving them but this word problem is driving me crazy. Here is the problem verbatim;
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Coordinate Systems and Linear Equations
-> SOLUTION: Hi appreciated tutors,
I have been studying linear systems and have a good understanding of solving them but this word problem is driving me crazy. Here is the problem verbatim;
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Question 968792: Hi appreciated tutors,
I have been studying linear systems and have a good understanding of solving them but this word problem is driving me crazy. Here is the problem verbatim;
The total cost of 10 gallons of regular gasoline and 15 gallons of premium gasoline is $32.75. Premium costs $.20 more per gallon than regular. What is the cost per gallon of each type of gasoline?
I tried to set up the problem like this:
x+y=25
10x+15y=32.75
I figured the .20 would be added to the final "y" value.
The way it comes out when I work the equations by trying to use substitution is a negative number. This is one indication I am working it incorrectly. Please show me a verbal model and work the equations and explain how to include the".20". THANKS very much!
You can put this solution on YOUR website! The total cost of 10 gallons of regular gasoline and 15 gallons of premium gasoline is $32.75. Premium costs $.20 more per gallon than regular. What is the cost per gallon of each type of gasoline?
=================
10R + 15P = 3275
P = R + 20
----------------
Sub for P
10R + 15*(R+20) = 3275
25R + 300 = 3275
R = 119
P = 139
You can put this solution on YOUR website!
let the cost of regular gasoline be , the cost of premium gasoline be
if the total cost of gallons of regular gasoline and gallons of premium gasoline is $, then
..........eq.1
if premium costs $.20 more per gallon than regular, then
The total cost is:
.....eq.2....solve for ...=>the cost per gallon of regular gasoline
now find the price of premium
...=>the cost per gallon of premium gasoline
check:
the total cost of gallons of regular gasoline is $
and gallons of premium gasoline is
then $=> $
