HELP With this please.

Tickets to a science exposition cost $5.75 each for studentd and $7.00 for adults. how many students and adults went if the ticket charge was $42.75

Stefano accidentally dropped his sunglasses off the edge of a canyon as he was looking down. the height, h(t), in meters (as it relates to sea level), of the sunglasses after t seconds, is shown in the table. during its descent, the pair of sunglasses passed by a climber in the canyon 6 seconds after stefano dropped them. to the nearest meter, what is difference in elevation between stefano and the climber? 166 meters 176 meters 230 meters 240 meters its b.176 i took the test 166 is wrong and 176 is correct

6x + 3y = -6 2x + y = -2 a. x = 0, y = -2 b. infinite solutions c. x = -1, y = 0 d. no solution