Solve the system by substitution x-y=-1 3x+2y=22

For number problems (or whatever its called) I use 
math way :p

For the first equation set the equation equal to x. (x=y-1) Then plug y-1 into the second equation. You should get 3(y-1)+2y=22, simplify that to 3y-3+2y=22, you can simplify that even more to 5y-3=22. In the end you should get for the y-value = 5. You can then plug 5 for y into (x-y=-1) or (3x+2y=22) or (x=y-1) and you will get the same answer. x = 4.
X = 4
Y = 5

B, 0.4 repeats so it is rational and square root of 16 is 4 so that is rational as well.