What is the image of (3,-3) after a dilation by a scale factor of 1/3 centered at the origin?

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

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?

Leslie started last week with $1200 in her checking account. during the week, she wrote the checks below.