SOLUTION: Jessica decides to mix grades of gasoline in her truck. She puts in 5 gallons of regular and 7 gallons of premium for a total cost of $29.44. If premium costs $0.16 more than reg

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Question 132951This question is from textbook Introductory Algebra
: Jessica decides to mix grades of gasoline in her truck. She puts in 5 gallons of regular and 7 gallons of premium for a total cost of $29.44. If premium costs $0.16 more than regular, what is the price of each grade of gasoline? This question is from textbook Introductory Algebra

Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!
($ are understood)
Let x=per gallon cost of regular
Total cost of regular=5x
Then x+0.16=per gallon cost of premium
Total cost of premium=7(x+0.16)
Now we are told that total cost of regular plus total cost of premium equals 29.44, so our equation to solve:
5x+7(x+0.16)=29.44 get rid of parens
5x+7x+1.12=29.44 subtract 1.12 from each side
5x+7x+1.12-1.12=29.44-1.12 collect like terms
12x=28.32 divide both sides by 12
x=$2.36 per gal-------------for regular
x+0.16=2.36+0.16=$2.52 per gal------------for premium
CK
5*2.36+7*2.52=29.44
11.80+17.64=29.44
29.44=29.44
Hope this helps---ptaylor