Answer:
Step-by-step explanation:
"The total number of dollars in fives and tens" tells you that these denominations are being added together. Because a five dollar bill is worth $5 and a ten dollar bill is worth $10, then the number of $5 bills is represented by 5f and a the number of $10 bills is represented by 10t. Therefore,
T = 5f + 10t
<span><u><em>Answer:</em></u>
The difference between successive terms is 10
<u><em>Explanation:</em></u>
To know the factor by which a certain pattern is increasing/decreasing, you need to subtract its successive terms.
If the subtraction gives you 10, this means that the pattern is increasing by 10
<u>Examples:</u>
<u>10, 20, 30, 40, 50, .....</u>
20 - 10 = 10
30 - 20 = 10
40 - 30 = 10
50 - 40 = 10
The difference between each two successive terms is 10. This means that each time we add 10 to the number we have in order to get the next one.
Therefore, this pattern is increasing by 10
<u>37, 47, 57 , .....</u>
47 - 37 = 10
57 - 47 = 10
The difference between each two successive terms is 10. This means that each time we add 10 to the number we have in order to get the next one.
Therefore, the pattern is increasing by 10
Hope this helps :)</span>
<u>Direct Variation:</u> 

when y = 7: 
14 = 15x

<u>Inverse variation:</u> y*x = k
15 * 2 = k
30 = k
when y = 7: 7 * x = 30

Option D should be the right answer