160 km because 20 hours times 8 km per hour
X intercept = -1, y = 0 (-1, 0)
<span>y intercept = 2, x = 0 (0, 2)
</span>
slope between (-1, 0) and (0, 2):
slope = (2 -0)/(0 - -1) = 2/1 = 2, m = 2
Using point (-1, 0) x₁ = -1, y₁ = 0
y - y₁ = m(x - x₁)
y - 0 = 2*(x - -1)
y = 2(x + 1)
y = 2x + 2
Add it. average= sum of 2 counts/2