Question

(x+y)^2(x+y)+1 is equivalent to​

Answer 1

Please explain the attached problem.

My take on it:

is (X+y)/ (x-y) > 1

ie. x + y > x -y

ie. 0 > y

which is B but OA is E.

If is ?

Is ? --> Is ? --> Is ? --> Is ?

(1) --> Not sufficient.

(2) --> Not sufficient.

(1)+(2) and --> numerator (y) is negative, but we cannot say whether the denominator {positive (x)+negative (y)} is positive or negative. Not sufficient.

Answer: E.

The problem with your solution is that when you are then writing , you are actually multiplying both sides of inequality by : never multiply an inequality by variable (or expression with variable) unless you know the sign of variable (or expression with variable). Because if you should write BUT if , you should write (flip the sign when multiplying by negative expression).

So again: given inequality can be simplified as follows: --> --> --> --> we can drop 2 and finally we'll get: .

Now, numerator is negative (), but we don't know about the denominator, as and can not help us to determine the sign of . So the answer is E.

Hope it helps.