Question I don't understand 12-16 I have been sitting here for over 3 hours trying to figure it out

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18. A boat 1.5 6/19 4. From 1960 to 1990 the cost to administer social and economic programs rose from \$1.9 billion to \$16 billion. The cost in billions can be modeled by f(x) =0.47x-919.3, where x is the year. Solve numerically or graphically for when the cost was \$6.6 billion. 5. Medicare costs in billions of dollars may be modeled by f(x) =18x-35, 750, where 1995 x 5 2007. Estimate the years when Medicare costs were from 250 to 340 billion dollars. 6. Solve 4-2x =1+x graphically. 7. Solve 4x-3&lt;5+2xgraphically and numerically. 8. Solve graphically and numerically: 5 x -1 = 2. 9. Solve -4&lt;2x+6&lt;12 graphically. 10. Solve the system graphically. Determine whether the system is consistent or inconsistent. a. xty = 6 x - y =-2 4x+ 2y =1 x-y=4 b. -2x + 2y = 4 C. 2x+ y= 5 11. Solve the system numerically. a. 3x+ y = 7 4x + 2y =-6 6x+ y =16 b. 3x - y =-7 12. The sum of two numbers is 25 and their difference is 10. Find the two numbers. 13. A student takes out two loans, one at 5% and the other at 7% annual interest. The total amount for both loans is \$7700 and the total interest after one year is \$469. Find the total amount for each loan. 14. At first an athlete runs at 8 miles per hour and then runs at 10 miles per hour, traveling 12.8 miles in 1.4 hours. How long did the athlete run at each speed? 15. The length of a rectangle is 5 feet longer than twice its width. If the rectangle has a perimeter of 88 feet, what are the dimensions of the rectangle? 16. During strenuous exercise, an athlete burns 1 1.5 calories per minute on a stair climber and 9 calories per minute on a stationary bicycle. In a 30-minute workout the athlete burns 290 calories. How many minutes are spent on each type of workout equipment? 8 NId  