CPhill

Good going, Melody.....!!!!   5 points from me!!!!.......yeah....it's not really that difficult.....!!!!!

Guest....look at the first part of the question, again...it's one side of the triangle whose vertices are (0,0), (b, 1/b) and (b, 0)

Oops....thanks, Guest....my bad!!!!!

Mellie.....this explains how to upload an image :  http://web2.0calc.com/questions/how-to-upload-an-image-nbsp_1

Also......your questions are difficult to read with all the LaTex (??) stuff......just submit them with "normal typing"...........

Good to see you on......CPhill

Let s be the side of the tile before the increase......and since the areas they cover are equal, we have:

1210s^2   = 1000(s + 1)^2   simplify

1210s^2  = 1000s^2 + 2000s + 1000     rearrange

210s^2 - 2000s -1000  = 0   divide through by 10

21s^2 - 200s - 100 = 0     factor

(21s + 10) (s -10) = 0

So  s = -10/21 cm......reject  ......or....... s =  10 cm

So.....the old tiles were 10 cm on each side and the "new tiles" are 11cm on each side

We have the points  (50,000, 3300)  and (70,000, 4100)......the slope is given by :

[ 4100 - 3300 ] / [ 70,000 - 50,000]  = 1/25  = .04

So  using this slope and either of the two points we can write a linear equation.....

y - 3300  = .04 (x - 50000 )   simplfy

y - 3300 = .04x - 2000      add 3300 to both sides

y = .04x + 1300

Here's the graph........https://www.desmos.com/calculator/isijxijsgu

No prob.......

Just put this into our onsite calculator and hit "enter"

Magic will happen.....!!!!!

I think the function is

C(x) = 0.3x + 100

The 100 is the "fixed cost"....in other words.....it costs you $100 before you even drive the first mile.....!!!!!.....so, on the graph of the function, we would have the point (0. 100)   = 0 miles driven = $100 cost

(2)   Set the function = 350 and solve....so we have

350  = 0.3x + 100   subtract 100 from both sides

250  = 0.3x   divide both sides by 0.3

x = about 833.33  miles.....this is how far you can drive for $350.......!!!!!

10/20-2+10     note ...  10/20  = 1/2....so we have

1/2 - 2 + 10  =

1/2  + 8   =

1/2 + 16/2   =

17/2