College Algebra
posted by LaScott Ellis on .
Maria Mixed grades of gasoline in her car, she puts 10 gallon of regular and 8 gallon of premium for a total $46.96. I f premium costs $0.20 more per gallon than regular, what was the price of each grade of gasoline.

10 r + 8 (r+.20) = 46.96
18 r + 1.60 = 6.96
18 r = 5.36 etc 
suppose charlie o'brian of the braves hits a baseball straight upward at 105ft/sec from a height of 5ft. I need to set up an equation because i need to use the formula to determine how long it takes the ball to return to the earth and estimate the height reached by the ball. I would like the steps as well as the answer.