Answer
a) $y=32x$
b) 128 feet per second
Work Step by Step
a)
1 second, 32 feet per second
3 seconds, 96 feet per second
$(1,32)$ and $(3,96)$ are the coordinates
$m=(96-32)/(3-1)$
$m =64/2$
$m=32$
$y=mx+b$
$32 = 1*32+b$
$32 = 32+b$
$0= b$
$y=32x$
b)
$y=32x$
At 4 seconds,
$y=32*4$
$y=128$
