Question

If x=-y and y>0, which of the following is wrong?
a) x^2y>0
b) x+y = 0
c) xy<0
d) 1/x - 1/y = 0​

Answer 1

Given: The value of x = -y and y > 0.

To find: Which of the following is wrong?

             a) x^2y>0

             b) x+y = 0

             c) xy<0

             d) 1/x - 1/y = 0​

Solution:

• Now we have given the value of x as -y, so putting them in all four options, we get:

           a) x² y > 0

                (-y)²y > 0

                y²y > 0

                y³ > 0  ......True as cube of positive number is always greater than 0.

           b) x+y = 0

                (-y) + y = 0

                0 = 0 ........True

           c) xy<0

                (-y)y < 0

                -y² < 0 True as the final answer is having negative sign.

           d) 1/x - 1/y = 0​              

                -1/y - 1/y = 0

                -2/y ≠ 0 False as the final answer is not 0.

• So 4 th option is wrong.

Answer:

         So among the four options, the fourth option 1/x - 1/y = 0​ is wrong.

Answer 2

Answer:

yes, the fourth option is wrong

1/x - 1/y = 0