Linear Systems 1 . Use your graphing calculator and linear regression to find the best fit line for each of these data tables . A ) x 1.5 0.8 3.5 8.5 6.8 7.5 Y 7.0 5.9 11.9 24.5 21.5 22.5 B ) x 12 9 3 11 7 2 Y 8 45 120 20 70 133 2 . Two large tanks are sitting next to one another . When an engineer started timing , the first tank had 2400L of oil in it while the second tank had only 985L in it . However , the first was losing oil at a rate of 35L every 8 minutes while the second tank was gaining oil at the rate of 42L every 5 minutes . Model the amount of oil in each tank using a linear equation . Carefully define the variables you use . After how many minutes will the two tanks have the same amount of oil in them ? A local high school produced a special yearbook for the graduating class . The following table was prepared by the business manager of the school . Number of Yearbooks Sold Production Cost Sales Revenue ( N ) ( C in $ ) ( S in $ ) 15 682.50 187.50 76 1262.00 950.00 124 1718.00 1550.00 255 2962.50 3187.50 312 3504.00 3900.00 1 . Use linear regression to find C as a function of N . 2 . Use linear regression to find S as a function of N . 3 . Write these two equations as a linear system using the variables x and y . 4 . Use your calculator to find the break-even point . Copy down the window settings that you used . 5. Use either substitution or elimination to solve the linear system that you developed in # 3 . Show all of your steps . 6. Use the linear system to calculate the profit or loss when 120 , 240 , 318 , and 146 books are sold . Show your calculations .