Anyone get burned at the beach

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

When 142 is added to a number the result is 64 more times the number my options are 35 37 39 41

When you have 25 numbers, and jake picks 3 random numbers and puts them back, what is the chance bob has of picking those 3 numbers when he picks 6 random numbers (without putting them back)? explain.