If the temperature rises 15° by noon and then rises 15 more degrees by 3 PM does the situation I have opposite quantities combine to make zero is a true or false?

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

Lines a and b are parallel. what is the value of x? -5 -10 -35 -55

2x minus y equals 6, x plus y equals negative 3