Two trains leave a city at 1 p. m. one train goes north at a constant rate of 75 mph. the other goes south at a constant rate of 63 mph. at what time will the trains be 621 miles apart?

Solve the system by the elimination method. 3x - 2y - 7 = 0 5x + y - 3 = 0 to eliminate y, the lcm is 2. which of the following is the resulting equations? 1.3x - 2y - 7 = 0 5x + y - 3 = 0 2.3x - 2y - 7 = 0 -10x - 2y + 6 = 0 3.3x - 2y - 7 = 0 10x + 2y - 6 = 0

While scuba diving, rajeev dove to a depth of 12.6 feet below the surface of the water and then descended another 8.7 feet. what expression can be used to find rajeev's new position? 12.6 – 8.7 –12.6 – 8.7 –12.6 – (–8.7) 12.6 – (–8.7)

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.