Re: x < 1/y, and x and y are positive
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03 Apr 2019, 02:29
First, let me break up each quantity:
Quantity A:
2x+xx−x2x=2x+1−x
Quantity B:
2y2y+yy−1y=2y+1−1y
Now subtract 1 from each quantity:
Quantity A: 2x−x
Quantity B: 2y−1y
Now we need some intuitive mathematical thinking. What if, instead of x<1y, we had x=1y? In that case, both quantities would be equal. Quantity A would become 21y−1y=2y−1y, same as quantity B.
In reality, though, x is a bit less than 1y. What happens when x gets smaller? Well, when x decreases, 2x increases, while the number we subtract, x, decreases. So when x gets smaller, quantity A gets larger.
Putting it all together, if x was equal to 1y, then both quantities would be equal. But x is actually a bit less than that, and as x decreases, quantity A increases while quantity B stays the same. Hence, quantity A is larger, no matter what.