If y varies directly as x, and y = 75 when X = 25. Find x when y=21 PLEASE HELP ASAP

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

If you had $1,900,000, how many days would it take you to spend all if you spent $1 a second. (there are 86,400 seconds in a day)

Two cyclists 84 miles apart start riding toward each other at the samen time. one cycles 2 times as fast as the other. if they meet 4 hours later what is the speed (in miles) of the faster cyclists