21 - 13.50= 7.50
so based on what your question is asking, Serena makes $7.50 more than Gabe per hour.
-2x + 6y = 6
6y - 6 = 2x
6(y-1) = 2x
(1/2) * 6(y-1) = 2x * (1/2)
x = 3(y-1)
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If, x = 3(y-1),
-7 * 3(y-1) + 8y = -5
-21 * (y-1) + 8y = -5
-21y + 21 + 8y = -5
21 + 5 = 21y - 8y
26 = 13y
y = 26/13
Therefore: y=2.
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If y=2,
x = 3(2-1) = 3
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Answers:
x=3 and y=2.
I think its 210 because there are 7 letters and 3 vowels so the permutation would be 7 P 3.
The difference between Tucker and Karly's take is that Tucker's solution is analytical while Karly's is graphical. But both are correct either way.
For Tucker's solution, let's say at x=-3 the value for y is 4, and at x=3, the value of y is still 4, then the average rate of change or slope is 0. Note that the slope of the curve is Δy/Δx. Since there is no change for Δy, the slope is zero.
For Karly's solution, even if the curve travels high or low but would have the same elevation of x=-3 and x=3, the average rate of change is still zero. It is actually just same with Tucker's but Karly just verbalizes her solution that was observed visually.