Question

19Which of the following shows that the sum of two irrational numbers can be rational?OA 1 / + v5OB. + 1OC. V2 + V2OD. (2 + v5) + (2 – V5)

Answer 1

The alternatives A, B and C results in irrational numbers. The only one that results in a rational number is D:

`(2+\sqrt[]{5})+(2-\sqrt[]{5})=2+2+\sqrt[]{5}-\sqrt[]{5}=4+0=4`

So, the alternative is D.