Answer:
I am not sure if this was the correct method to solve the question, however it gives the right results if you check it.
Step-by-step explanation:
3x+250+100=1250
3x= 900
x=300
yoga: 300, cross fit: 550 (300+250), gym: 400(300+100)
Let's begin by listing out the information given to us:

We are to find the value of y
If you mean y=2x+12 then the line crosses at positive 12