(5,60)(10,40)
slope = (40 - 60) / (10 - 5) = - 20/5 = -4
y = mx + b
slope(m) = -4
(5,60)...x = 5 and y = 60
now we sub and find b, the y int
60 = -4(5) + b
60 = -20 + b
60 + 20 = b
80 = b
equation is : y = -4x + 80
function form : f(x) = -4x + 80...where x = number of weeks and f(x) = loads of waste removed
The answer is (3,-4) because it machtes up with (-5,-4) and (3,4), so it (3,-4) is correct.
1, 3, 9 and -1, -3, and -9 i guess
hope this helps