The cost of three notebooks and four pencils is $7.20. the cost of five notebooks and eight pencils is $13.20. write a system of equations to model this situation. how much does one pencil and one notebook cost?

Notebook cost = $1.2

Pencil cost = $ 0.9

Step-by-step explanation:

Call x at the cost of each notebook and call z at the cost of each pencil.

So we know that 3x added with 4z equals $ 7.20

So:

   (i)

We also know that 5x and 8z = $13.20

Then:

   (ii)

Finally we have a system of 2 equations (i), (ii) and two unknowns x and z.

Then we can solve the system by doing:

-2(i) + (ii)

We have left:

       +

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Now we substitute the value of x in equation (i) and clear z.

step-by-step explanation:

once you graph it hit 2nd (the blue button) and graph

that takes you to a table of coordinates

on the left is x coordinates and on the right is y coordinates and an empty box

(you may have to scroll up/down in order to get ( x, 0)

step-by-step explanation:

let's assume

number of candles set =x

price of of x candles =p(x)

we are given

a candle maker prices one set of scented candles at $10 and sells an average of 200 sets each week

so, we get point as (200,10)

he finds that when he reduces the price by $1, he then sells 50 more candle sets each week

so, we can find slope

now, we can use point slope form of line

now, we can plug values

we can use point

and find b

now, we can plug it back

and we get

now, we can find revenue

we know that

revenue = price*quantity

so, we get