Solve for X. Help me if you know

What term makes it inconsistent y=2x - 4 ?

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

Atest consists of 10 multiple choice questions, each with 5 possible answers, one of which is correct. to pass the test a student must get 60% or better on the test. if a student randomly guesses, what is the probability that the student will pass the test?