parallel lines, have the same exact slope, hmmm what is the slope of y = -2/3 x + 1/3 anyway? well, low and behold, the equation is already in slope-intercept form, therefore
has a slope of -2/3.
so we're really looking for a line whose slope is -2/3 and runs through 9,4.

The answer would be x^4 -16
Explanation: use the FOIL method.
(x^2 +4)(x^2 -4)= x^4 +4x -4x -16. 4x and -4x cancel each other out. You are left with x^4 -16.
F- irst
O- uter
I- nner
L- ast
Answer:
Solution given:
model A printers [a] prints=80books per day
model B printers [b] prints=55books per day
total no of printers =9
no of model A printers be x
and
no of model B printers be [9-x]
According to the question;
ax+(9-x)b=670 books
substituting value of a and b; we get
80x+(9-x)55=670
80x-55x+495=670
25x=670-495=175
x=
=7
So;
no of model A printers =x=<u>7</u>
no of model B printers =9-x=9-7=<u>2</u>
<u>is</u><u> </u><u>your</u><u> </u><u>answer</u><u>.</u>

The last line is in vertex form, and can see the vertex is located at (2,1).