Can someone please help me?

If x = 12 and y = 3, what is the value of x - y 2? 81 6 3 18

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

Someone answer asap for ! the following statements are true about the coins calvin and sasha have collected. * calvin and sasha has the same amount of money. * calvin has only quarters. * sasha has dimes, nickels, and pennies * calvin has the same number of quarters as sasha has dimes. * sasha has $1.95 in coins that are not dimes. exactly how many quarters does calvin have?