Section 1.5Rewriting Equations and Formulas41 31. REWRITING A FORMULA A common statistic used in professional football is the quarterback rating. This rating is made up of four major factors. One factor is the completion rating given by the formulaR 5 ( C — A 0.3 ) where C is the number of completed passes and A is the number of attempted passes. Solve the formula for C. 32. REWRITING A FORMULA Newton’s law of gravitation is given by the formulaFG(m1m2—d2 ) where F is the force between two objects of masses m1 and m2, G is the gravitational constant, and d is the distance between the two objects. Solve the formula for m1. 33. MODELING WITH MATHEMATICS The sale price S (in dollars) of an item is given by the formula S L rL, where L is the list price (in dollars) and r is the discount rate (in decimal form). (See Examples 4 and 6.) a. Solve the formula for r. Sale price:$18Sale price:$18 b. The list price of the shirt is $30. What is the discount rate? 34. MODELING WITH MATHEMATICS The density d of a substance is given by the formula d m — V , where m is its mass and V is its volume.Density: 5.01g/cm3 Volume: 1.2 cm3Pyrite a. Solve the formula for m. b. Find the mass of the pyrite sample. 35. PROBLEM SOLVING You deposit $2000 in an account that earns simple interest at an annual rate of 4%. Howlong must you leave the money in the account to earn $500 in interest? (See Example 7.) 36. PROBLEM SOLVING A  ight averages 460 miles per hour. The return  ight averages 500 miles per hour due to a tailwind. The total  ying time is 4.8 hours. How long is each ight? Explain. (See Example 8.) 37.USING STRUCTURE An athletic facility is building an indoor track. The track is composed of a rectangle and two semicircles, as shown.xrr a. Write a formula for the perimeter of the indoor track. b. Solve the formula for x. c. The perimeter of the track is 660 feet, and r is 50 feet. Find x. Round your answer to the nearest foot. 38. MODELING WITH MATHEMATICS The distance d (in miles) you travel in a car is given by the two equations shown, where t is the time (in hours) and gis the number of gallons of gasoline the car uses.d = 55td = 20g a. Write an equation that relates g and t. b. Solve the equation for g. c. You travel for 6 hours. Howmany gallons of gasoline does the car use? Howfar do you travel? Explain.