Solve using addiction method show all work. 4x=5y+6 3y+2x=-8

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

Three students each examine the system of linear equations shown. 8x + 4y = 16 8x + 2y = 8 caleb says there is exactly one solution. jeremy says there is no solution. kim says there are infinitely many solutions. which student is correct? provide mathematical reasoning to support your answer. answer in complete sentences. : d

Apasta salad was chilled in the refrigerator at 35° f overnight for 9 hours. the temperature of the pasta dish dropped from 86° f to 38° f. what was the average rate of cooling per hour?