AE wrote:
Carcass wrote:
\(|x| > |y|\) and \(x + y > 0\)
Quantity A |
Quantity B |
y |
x |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Kudos for
R.A.EGiven
\(|x| > |y|\)
\(x^2 > y^2\)................we can do it safely as both x and y are in absolute value sign.
\(x^2 - y^2 >0\)
(x + y) (x -Y) > 0
We know x + y> 0 , thus x - y> 0
So, x - y >0 or x>y.
The best answer is B.
But (x + y) (x -Y) > 0 means either x + y> 0 , or x - y> 0
Given x + y> 0 does not mean that x - y> 0 In this case we are lucky.
Is there any other approach please?
hi..
(x + y) (x -Y) > 0 means either 'both (x + y) and (x -Y) are greater than 0' or 'both (x + y) and (x -Y) are less than 0' because + * + =+ and -*-=+
so if x=y>0, x-y will also be greater than 0.
Another approach will be logical ..
|x|>|y| can be written as |x-0|>|y-0|, so distance of x from 0, is more than y from 0.
so x+y will depend on the sign of x, if x is negative (x+y) will be negative and if x is positive, (x+y) will be positive..
so we are given x+y>o, which means x>0..
if x>0, |x|=x, so x>|y|..
y will be equal or less than |y|, so x>y
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Some useful Theory.
1. Arithmetic and Geometric progressions : https://greprepclub.com/forum/progressions-arithmetic-geometric-and-harmonic-11574.html#p27048
2. Effect of Arithmetic Operations on fraction : https://greprepclub.com/forum/effects-of-arithmetic-operations-on-fractions-11573.html?sid=d570445335a783891cd4d48a17db9825
3. Remainders : https://greprepclub.com/forum/remainders-what-you-should-know-11524.html
4. Number properties : https://greprepclub.com/forum/number-property-all-you-require-11518.html
5. Absolute Modulus and Inequalities : https://greprepclub.com/forum/absolute-modulus-a-better-understanding-11281.html