Simple Fuel Efficiency

2) Given 5x^2+21x-20=0, what is the sum of the roots? What is the product of the roots?

3) use the discriminant to determine the number of real solutions of the equation: 4x^2-3x-7=0

4) Solve the inequality algebraically: x^2+x >or= 42

5) a small airline's profit is dependent upon the number of seats it sells. however, fuel efficiency is dependent upon the weight of the airplane. the equation P(x)=-86x^2+1290x-4300 gives the profit, P(x), of each flight dependent upon how many passengers, x, are on each flight. Between what numbers of passengers does the airline make a profit?

6) write 11x^(7/12) using radical notation. assume that all variables represent positive real numbers.

7) evaluate 81^(-3/4)

evaluate the fourth root of 405 using a calculator. Round the results to three decimal places when appropriate. (how do i do this?)

9)write the expression in simplest form: sqrt{(64x^2y^3)/(4x^6y)}