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Inequalities

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by adthedaddy » Thu Sep 24, 2015 7:23 pm
If x and y are positive integers, is

root(x+y+1) > 3root(x+1) ?

1. y > 8x + 8
2. x+y > 8x + 8

Standard DS options follow.

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Source: — Data Sufficiency |

by Matt@VeritasPrep » Fri Sep 25, 2015 12:44 am
Let's start by squaring both sides:

is (x + y + 1) > 9(x + 1) ?

or

is x + y + 1 > 9x + 9 ?

or

is y > 8x + 8 ?

S1 says YES, y IS > 8x + 8.

S2 says MAYBE. y > 7x + 8, but we don't know if y > 8x + 8.
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