For question 39 & 40, we need to use the below equation to complete the sentence

Question 39:
When ' n ' increase, the  will also increase and that multiplied with constant ' m ', the l will also increase.
 will also increase and that multiplied with constant ' m ', the l will also increase. 
Solution for question 39:
As  increases and
 increases and  stays constant ,
 stays constant ,  <u>increases</u>
 <u>increases</u>
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Question 40:
Solving the equation for m, we get

When ' l ' increases, the numerator increase, the denominator stays constant because 'n' stays constant, for this condition, the fraction increases.
Solution for question 40:
As  increase and
 increase and  stays constant,
 stays constant,  <em><u>increases</u></em>
 <em><u>increases</u></em>
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For question 41 & 42, we need to use the below equation to complete the sentence

Question 41:
When  is triped, the equation will be...
 is triped, the equation will be...

Solution for question 41:
If  is tripled and
 is tripled and  stays constant,
 stays constant,  is multiplied by <em><u>9</u></em>
 is multiplied by <em><u>9</u></em>
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Question 42:
When t is doubled, the equation will be...

Solution for 42:
If  doubled and
 doubled and  stays constant,
 stays constant,  is multiplied by <em><u>1/4 or 0.25</u></em>
 is multiplied by <em><u>1/4 or 0.25</u></em>