Help me with my math work please! A train is moving at a constant speed. the graph above shows the distance-time relationship for the train, where x represents the time, in hours, and why represents the distance traveled, and kilometers.

which function represents the distance-time relationship shown on the graph?

A. y = 80x
b. y = 200 x
c. y = x + 80
d y = 2.5 x + 200​

Answer is      (1/2)y - (1/2)x======x = log 3 and y = log 21note that 21 factors into 3 and 7 so    y = log 21    y = log(7  · 3)use log law that says      y = log(7) + log(3)and since x = log(3):     y = log(7) + xsolve for log(7) to get    log 7 = y - xnow focusing on    use log law  with      since log 7 = y - x