please need help , and if possible can show work . What is the value of x in the equation 1/5x-2/3y=30 when y=15

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?

Twenty-five percent of the customers entering a grocery store between 5 p.m. and 7 p.m. use an express checkout. consider five randomly selected customers, and let x denote the number among the five who use the express checkout.

Pls me this is due today and i need i will make brainliest if you me answer correctly and i will report if you try to give me a dumb answer.