Which of the following determines a plane?

Will mark ! (10 points also! ) if x varies inversely with y and x =6 when equals y= 10, find y when x=8 a. y=4.8 b. y=7.5 c. y=40/3 d. y=4/15

The deepest part of the swimming pool is 12 feet deep. the shallowest part of the pool is 3 feet deep. what is the ratio of the deeply of the deepest part of the pool to depth of the shallowest part of a pool?

Solve the system of equations. y=3x-1 and y=-2x+9. show work