Unit Rate IS the Slope!
unit rate = k = y ÷ x → y = kx
In a proportional relationship, the unit rate tells how much y changes for every 1 unit of x — that's the slope of the line.
1
From a table: pick any column and divide y by x.
Time 2s, 1.6 gal → 1.6 ÷ 2 = 0.8 gal/s
2
From a graph: pick a point on the line and divide y by x.
Point (4, 3) → 3 ÷ 4 = 0.75 gal/s
3
To compare: find each unit rate, then the bigger rate is faster!
0.8 gal/s > 0.75 gal/s → Machine B wins