Rewrite the boundary lines <em>y</em> = -1 - <em>x</em> and <em>y</em> = <em>x</em> - 1 as functions of <em>y </em>:
<em>y</em> = -1 - <em>x</em> ==> <em>x</em> = -1 - <em>y</em>
<em>y</em> = <em>x</em> - 1 ==> <em>x</em> = 1 + <em>y</em>
So if we let <em>x</em> range between these two lines, we need to let <em>y</em> vary between the point where these lines intersect, and the line <em>y</em> = 1.
This means the area is given by the integral,
The integral with respect to <em>x</em> is trivial:
For the remaining integral, integrate term-by-term to get
Alternatively, the triangle can be said to have a base of length 4 (the distance from (-2, 1) to (2, 1)) and a height of length 2 (the distance from the line <em>y</em> = 1 and (0, -1)), so its area is 1/2*4*2 = 4.
The GCF of the three terms (9a, -18b and 21c) is 3
Rewrite each of the terms so 3 is a factor
9a = 3*3a
-18b = -3*6b
21c = 3*7c
So we can say...
9a - 18b + 21c = 3*3a - 3*6b + 3*7c
9a - 18b + 21c = 3(3a - 6b + 7c)
Answer: 3(3a - 6b + 7c)
If you distribute outer 3 to each of the inner terms and multiply, you'll get the original expression again.
Work:
A 12-pack of boxes is 4 3-pack of boxes, I found this by dividing 12 by 3.
A 24-pack of boxes is 2 12-pack of boxes, found by dividing 24 by 12.
A 24-pack of boxes is 8 3-pack of boxes, found by dividing 24 by 3 or by multiplying the two previous together (sometimes may not work)
Multiply
$1.09 × 4
That gets you to $4.36, which is less than the price of a 12-pack of boxes.
Then, multiply
$4.39 × 2
That gets you $8.78, which is less than a 24-pack of boxes.
Finally, multiply
$1.09 × 8
That gets you $8.72, which is less than a 24-pack of boxes.
Answer:
The best to buy is the 3-pack of boxes of juice, because it is cheaper when buying multiple of the 3-packs than it is to buy one or more of the 12-pack or 24-pack.
Hope this helps anyone with the question.
