Re: x + y < 0 y – x > 0
[#permalink]
22 Jul 2019, 07:02
Subtract x from both sides of the first inequality:
y < -x
Add x to both sides of the second inequality:
y > x
Combine the two:
-x > y > x
Note that if -x > x, x must be negative and -x must be positive.
Now imagine this on a number line:
<-----(x)--------(y)--------(-x)------>
We know that 0 must be somewhere between x and -x, and we know that y must be somewhere between x and -x, but we don't have any way to compare 0 and y, so the answer must be D.
You can also solve this by picking numbers, although even then I'd recommend the number line because it helps you see which numbers would be good to pick.
-Jordan Wolbrum