Can someone please help Write an equation for these
y = mx+b
The first one is given:

Between 0 and 3 sec.
y = 30

Between 3 and 5.5 sec.

Between 5.5 and 7 sec.

Between 7 and 8.5 sec.

Between 8.5 and 9 sec.

Between 9 and 11 sec.

Between 11 and 12.7 sec.

Between 12.7 and 13 sec.