Answer:
y = 3, x = 3
Step-by-step explanation:
5x – 3y = 6
5x = 6 + 3y
x = (6 + 3y)/5
3x + 4y= 21
3x = 21 - 4y
x = (21-4y)/3
Using simultaneous equations:
(21-4y)/3 = (6 + 3y)/5
--> 105-20y = 18 + 9y
29y = 87
Answer:
0.5
Step-by-step explanation:
Answer:
The dimensions of the smallest piece that can be used are: 10 by 20 and the area is 200 square inches
Step-by-step explanation:
We have that:

Let the dimension of the paper be x and y;
Such that:


So:

Substitute 128 for Area

Make x the subject

When 1 inch margin is at top and bottom
The length becomes:


When 2 inch margin is at both sides
The width becomes:


The New Area (A) is then calculated as:

Substitute
for x

Open Brackets

Collect Like Terms



To calculate the smallest possible value of y, we have to apply calculus.
Different A with respect to y

Set

This gives:

Collect Like Terms

Multiply through by 


Divide through by 2

Take square roots of both sides



Recall that:



Recall that the new dimensions are:


So:




To double-check;
Differentiate A'




The above value is:

This means that the calculated values are at minimum.
<em>Hence, the dimensions of the smallest piece that can be used are: 10 by 20 and the area is 200 square inches</em>
Answer:
x-4y+12
Step-by-step explanation: