Can someone help me out? Thanks a lot! :)

Find the solution of this system of equation -7x+y=-20 9x-3y=36

The revenue each season from tickets at the theme park is represented by t(c)=5x. the cost to pay the employees each season is represented by r(x)=(1.5)^x. examine the graph of the combined function for total profit and estimate the profit after four seasons

Kai walked one and two-thirds of a mile on saturday and four and one-sixth of a mile on sunday. how many miles did kai walk?