Question

A school system is reducing the amount of dumpster loads of trash removed each week. In week 5, there were 60 dumpster loads of waste removed. In week 10, there were 40 dumpster loads removed. Assume that the reduction in the amount of waste each week is linear. Write an equation in function form to show the amount of trash removed each week.

f(x) = −4x + 60
f(x) = 4x + 60
f(x) = −4x + 80
f(x) = 4x + 80

Answer 1

Any ideas?

Answer 2

Okay - Do you know why you would've came up with that?

Answer 3

nvm. Its C

Answer 4

because they are removing 4 dumpster loads per week

Answer 5

so I know its -4x. But I was in between A and C. I tried A the first time and it was wrong. Now I tried it again and its C

Answer 6

But Im not 100% how its C though. If anyone can explain...

Answer 7

@dude

Answer 8

Ok

So it gave you two points, x is weeks, y is loads :)

The points they gave you would be written as (x,y) -> (5,60) and (10,40)

You basically want to find the slope between both by using the equation
\(\frac{\Delta y}{\Delta x}\) (Are you familiar with this?; Can be written as \(\large \frac{y_2-y_1}{x_2-x_1}\))

Answer 9

Yes, I am familiar with it :). Thank you so much for the explanation

Answer 10

Well I mean it's not fully worked out yet

Once you find that, it gives you the slope (-4)

You can logically work out that since it goes down 4 and was at 60 in week 5, work the other way around to find week 1 to find the start (Add 5 four times)

You would get 80

Hence,
\(f(x)=-4x+80\)

Answer 11

Yeah I found the slope but by some reason I potatoed and put -4x +60 instead of -4x +80. Thank you