algebra
posted by Emma .
Use the substitution method to solve the linear system. Thanks!
s= t+4
2t+s=19

s= t+4
2t+s=19
2t + t + 4 = 19
3t = 15
t = 5
s = 5 + 4
s = 9 
I have another question.
So I solved the problem but then I have to put it in an ordered pair form. If I was using the variables "x and y," then it would be (x,y) but what if I were using different variables, in this case s and t, how do I know which one is the x and which one would be the y? 
I don't know. Please post your last question as a new question.

since you started out with s = t+4
I bet you want to use s for y and t for x
However there is no way for me to tell from what you wrote which is the dependent variable y and which is the independent variable x