The variables y and x have a proportional relationship, and y=7 when x=2. What is the value of x when y=21?

Someone this asap for a group of students attends a basketball game. * the group buys x hot dogs at the concession stand for $2 each. * the group buys y drinks at the concession stand for $3 each. the group buys 29 items at the concession stand for a total of $70. how many hot dogs did the group buy?

What statement is true? 2x^2-9x+2=-1

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25