Question

Which statement is true about the difference 2 square root of 7 − square root of 28? It is rational and equal to −2. It is rational and equal to 0. It is irrational and equal to −2square root of 7. It is irrational and equal tosquare root of 7.

Answer 1

$2\sqrt{7} - \sqrt{28} = 2 \sqrt{7} - \sqrt{4 \times 7 } =2 \sqrt{7} - 2 \sqrt{7 } = 0$