GO LIKE my answers i posted plzzz

What is the length x of the side of the triangle below? (hint: use the cosine function)

From center station, a train departs every 30 minutes on the fast line and a train departs every 50 minutes on the state line. if two trains depart from center station at 8: 00 a.m., one on each of the two lines, what is the next time that two trains, one on each line, will depart at the same time?

If 21.2 kcals of energy is released by this reaction, how many kj does the reaction release? (1 cal 4.184 j)