Someone help me please

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

The longer leg of a 30° 60° 90° triangle is 16 times square root of three how long is a shorter leg

The perimeter of a rectangular lot of land is 436 ft. this includes an easement of x feet of uniform width inside the lot on which no building can be done. if the buildable area is 122 ft by 60 ft, determine the width of the easement. select one: a. 9 feet b. 18 feet c. 4.5 feet d. 7 feet