Answer:
D
Step-by-step explanation:
So first, we have to test the pairs. Let start with equation 1.
7=\=3 x
4=\=2 x
0=0 ✓
4=4 ✓
Now we only have to test B and D.
0=\=-1
4=4 ✓
D is the correct answer.
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:
c) multiply the numerators, multiply the denominators, and then simplify.
Step-by-step explanation:
Answer:
x = 3 ± 
or
x = 3 +
, x = 3 - 
Step-by-step explanation:
given f(x) = 2(x - 3)^2 - 8, find when f(x) = 40
So, we plug in 40 for f(x) in the 1st equation and solve for x. (Aim to got x on its own)
40 = 2 (x - 3)^2 - 8
+ 8 + 8
-----------------------------
48 = 2 (x - 3)^2
/2 /2
-----------------------------
24 = (x - 3)^2
square root both sides
--------------------
= x - 3
x = 3 ± 
(1)
10(1+3x)=-20
Cross multiply.
10+30x=-20
Isolate x on one side. So you would subtract 10 on each side. and one side will cross each other out. leaving you with,
30x=-20-10
Subtract 10 from -20.
30x=-30
Divide each side by 30 to get x.
30x÷30=-30÷30
Therefore,
x=-1
(2)
-5x-8(1+7x)=-8
Cross multiply -8(1+7x)
-5x-8-56x=-8
Isolate all x's on one side. So you would add 8 on each side. and one side will cross each other out. leaving you with,
-5x-56x=-8+8
Add 8 to -8.
-5x-56x=0
Subtract -56x from -5x
-61x=0
Divide each side by -61
-61x÷-61=0÷-61
Therefore,
x=0