Question

The following are the slopes of the lines repre-
senting daily revenues y in terms of time x in
days. Use the slopes to interpret any change
in daily revenues for a 1-day increase in time.
a) m = 400
1. The revenues are decreasing $400 per day
2. Unable to determine
3. The revenues are increasing $400 per day

Answer 1

@tkhunny

Answer 2

Why not explore it anc create your own experiment?

y = 400x + b

Try something. Maybe x = 10.
Okay, now try x = 11 - a one day increase. What happened?

Answer 3

the revenues are decreasing 400 per day?

Answer 4

Notice how one need not find the intercept at all!

Answer 5

@lasttccasey can you help me

Answer 6

Well a positive slope generally means increase over the x interval which in this case would be time. So I would assume the answer to be:
3. The revenues are increasing $400 per day

Answer 7

@raffle_snaffle

Answer 8

Did you compare x = 10 and x = 11? It will tell you what happens.

y = 400x + b

Answer 9

let me do it hang on

Answer 10

increase?

Answer 11

(400(11) + b) - (400(10) + b) = 400(11-10) = 400

Oh, so the increase of one day creates an increase of 400.

Answer 12

@tkhunny how about m=100?

Answer 13

Explore it!! Do what I just did and see what happens.

Answer 14

@tkhunny it would be the same thing, an increase right

Answer 15

Slope is 100, increase is 100.
Slope is 400, increase is 400.
Slope is -40, decrease is 40.

It's the nature of a linear function. It all happens together and at the same rate and in the same direction.

Answer 16

how about if it was 0?

Answer 17

@tkhunny

Answer 18

Why would it be any different?