slope intercept form is y=mx+b
So slope intercept form is The office manager of a small office ordered 140 packs of printer paper based on average daily use, she knows that the paper will last about 80 days
(A) Lets make a table
X axis represents the Number of days paper used
y axis represents the packs of printer paper used
x y
days packs of printer paper used
0 0 (0 days , 0 packs used)
80 140 (in 80 days , 140 packs paper used)
The graph is attached below
(B) To find Equation of a line we use points (0,0) and (80,140)
![slope = (y_2-y_1)/(x_2-x_1) = (140-0)/(80-0) = (7)/(4)](https://img.qammunity.org/2019/formulas/mathematics/high-school/qnnrc57hvms7bfeyfmnnq0gwhrkv22ubpo.png)
y intecept is (0,0)
so b= 4
Slope intercept form of a line i y=mx + b
m is the slope and b is the y intercept
So slope intercept form of line becomes
![y= (7)/(4) x](https://img.qammunity.org/2019/formulas/mathematics/high-school/zu16lnzov6h18ve3b7ucv89q33wqfptchc.png)
Standard form is Ax + By =C
![y= (7)/(4) x](https://img.qammunity.org/2019/formulas/mathematics/high-school/zu16lnzov6h18ve3b7ucv89q33wqfptchc.png)
Multiply both sides by 4
4y = 7x
Now subtract 7x on both sides
-7x + 4y =0 is the standard form
(c) To find packs of printer paper the manager expect to have after 30 days, Plug in 30 for x and find out y
![y= (7)/(4) x](https://img.qammunity.org/2019/formulas/mathematics/high-school/zu16lnzov6h18ve3b7ucv89q33wqfptchc.png)
![y= (7)/(4)(30)= 52.5](https://img.qammunity.org/2019/formulas/mathematics/high-school/p0qe2dn4c6x137btco3erwa319cfbtmdj0.png)
Total 140 packs of printer paper
52.5 packs of paper used
Packs of paper remaining after 30 days = 140- 52.5= 87.5