How do you simplify 12a - 22b - 32a + 42b - 52

Liam's parents are driving three times as fast as liam is biking, but they left later than he did. if his parents caught up with him two hours after he left, how much later than liam did they leave?

For one history test, keith had to answer 40 questions. of these 40 questions, keith answered 28 of them correctly. what percent did keith get on his history test? round your answer to the nearest tenth if necessary

Ascatter plot with a trend line is shown below. which equation best represents the given data? y = x + 2 y = x + 5 y = 2x + 5