Solving system of equations

1.x=3+y
x+4y=6

How do i solve uniform motion problems?

The difference between two numbers is one. three times the larger number minus two times the smaller number is 9. what are the two numbers

The number of calories you burn depends on your weight. a 110-pound person burns 163 calories during 30 minutes of tennis. find the number of calories that a 190-pound person would burn during the same activity, assuming they burn calories at the same rate.