Answer: Choice B) 
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Work Shown:
This shows why choice B is the answer.
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Explanation:
- In the second step, I multiplied top and bottom by
- This is so we can apply the difference of squares rule in step 3. The difference of squares rule is (x-y)(x+y) = x^2-y^2.
- In step 4, the square roots cancel out with the squaring operation. The two operations are inverses of one another, which is why they cancel.
So in general, if the denominator is 
and you want to rationalize the denominator, then you should multiply top and bottom by 
. The same applies in reverse as well.
This leads to the denominator becoming 
Keep in mind that 
and 
A. 14 (7x2=14)
b. 8 (8x3=24)
c. 11 (no other numbers except 1 and 11 multiply to get 11)
On the sheet, it's not even asking you for the dimensions.
It's just asking you to set up the <em>equation that you would use</em>
to find the dimensions. That's a great way to do it, because
nobody actually needs the answers, the whole thing is only
meant to help you learn HOW to find them.
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Call the width of the window 'W' .
We know that the length is 5 feet more than the width, so the length is (W + 5).
The area is (length times width).
Area = (W + 5) times (W).
36 = (W + 5) W
36 = W² + 5W
Subtract 36 from each side:
W² + 5W - 36 = 0
That's choice-4 .
Answer:
B. 4m
Step-by-step explanation:
What you do is you just take the 8 and put it into the m.
m-8, 8-8=0 so A isn't your answer.
4m, 4(8)=32 so B is your answer.
B. 4m is your answer.
