Question

The graph shows the number of gallons in a wading pool that is being drained. Using the points (1,160)
(
1
,
160
)
and (3,80)
(
3
,
80
)
as (x1,y1)
(
𝑥
1
,
𝑦
1
)
and (x2,y2)
(
𝑥
2
,
𝑦
2

Answer 1

Slope m = (y2 − y1)/(x2 − x1) = (80 − 160)/(3 − 1) = −80/2 = −40.

Point‑slope: y − 160 = −40(x − 1) → y = −40x + 200.

Interpretation: the pool is losing 40 gallons per unit of x (e.g., per minute). At x = 0 there are 200 gallons; the pool will be empty when 0 = −40x + 200 → x = 5.