How do you solve this using the substitution method?

x=13, y=36

Step-by-step explanation:

y−2x=10

6x−2y=6  −2x+y=10

6x−2y=6

6x=2y+6

x=  1/6(2y+6)

x=1/3y+1

-2(1/3y+1)+y=10

-2/3y-2+y=10

1/3y=12

y=36

Substitute y  to check your answer

x=1/3*36+1

x=12+1

x=13

And to go further if you wish to check your answer you can substitute x

Let's add up all of the other sports except baseball (which we don't know)
1/3 + 1/8 + 5/12   Common denominator is 24 so let change them to 24ths

8/24 + 3/24 + 10/24 = 21/24   Since all the sport put together can be represented by the number 1, we will do 1 - 21/24
Instead of 1, I will use 24/24 (which means 1)     

24/24 - 21/24 = 3/24  or 1/8 reduced.   1/8 of the student named baseball as their favorite sport.