Answers:
- The lengths of sides PQ and RS are <u> 13 </u>
- The lengths of sides QR and SP are <u> </u><u>20 </u>
This is a 13 by 20 rectangle.
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Explanation:
Refer to the drawing below.
Let x be the length of side SP. Since we're dealing with a rectangle, the opposite side is the same length. Side QR is also x units long.
We're told that RS = SP - 7 which is the same as saying RS = x-7
We also know that PQ = x-7 as well because PQ is opposite side RS.
In short, we have these four sides in terms of x
- PQ = x-7
- QR = x
- RS = x-7
- SP = x
as shown in the drawing. The four sides add up to the perimeter of 66.
PQ+QR+RS+SP = perimeter
PQ+QR+RS+SP = 66
(x-7)+x+(x-7)+x = 66
4x-14 = 66
4x = 66+14
4x = 80
x = 80/4
x = 20
Use this x value to find the unknown side lengths.
- PQ = x-7 = 20-7 = 13
- QR = x = 20
- RS = x-7 = 20-7 = 13
- SP = x = 20
In short, this is a 13 by 20 rectangle.
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Check:
perimeter = side1+side2+side3+side4
perimeter = PQ+QR+RS+SP
perimeter = 13+20+13+20
perimeter = 33+33
perimeter = 66
The answer is confirmed.
So let's see here...
6:00 A.M. temperature is 33°F.
12:00 P.M temperature increased by 10°F making it 43°F.
3:00 P.M. temperature increased by another 12°F making it 55°F.
At 10:00 P.M it would decrease by 15°F making it 40°F.
The temperature would need to fall (or decrease) by 7°F to reach the original temperature of 33°F
Hope this helped!
Answer: IXL
Step-by-step explanation:
Answer:
6000 ft
Step-by-step explanation:
Let length of rectangular field=x
Breadth of rectangular field=y
Area of rectangular field=
square ft
Area of rectangular field=
Area of rectangular field=


Fencing used ,P(x)=
Substitute the value of y
P(x)=

Differentiate w.r.t x

Using formula:





It is always positive because length is always positive.
Again differentiate w.r.t x

Substitute x=1500

Hence, fencing is minimum at x=1 500
Substitute x=1 500

Length of rectangular field=1500 ft
Breadth of rectangular field=1000 ft
Substitute the values
Shortest length of fence used=
Hence, the shortest length of fence that the rancher can used=6000 ft
Answer:

So it would takes approximately 6.9 hours to reach 32 F.
Step-by-step explanation:
For this case we have the following differential equationÑ

We can reorder the expression like this:

We can use the substitution
and
so then we have:

IF we integrate both sides we got:

If we apply exponential in both sides we got:

And if we replace w = u-T we got:

We can also express the solution in the following terms:

For this case we know that
since w ehave a cooloing,
, we have this model:
And if we want that the temperature would be 32F we can solve for t like this:



If we apply natural logs on both sides we got:


So it would takes approximately 6.9 hours to reach 32 F.