now, this is pretty much the same as the one before it with Jaime, so I'll do this without much fuss.
recall d = rt.
a = Alfonso's rate
with the wind his speed is a + 5, against it is a - 5, 60 miles with it and 30 miles against it, all in the same time of t hours.

Answer:
It allows to to know y-intercept formula which is used to graph a line.
Step-by-step explanation:
Y-intercept formula:
y=mx+b
M: slope (keep in fraction if it is fraction, to help you graph)
B: y-interecept
2nd or 4th option, they appear to be the same