Verified answer

rational number - A number capable of being expressed as an integer or a quotient of integers, excluding zero as a denominator.

In other words, a number that can be written as a fraction.

So looking at our choices,

-1 can be written as a fraction (-1/1)

0 can be written as fraction (0/1)

1/7 already is a fraction

So by process of elimination, √6 is your answer. If you woant the explanation why, it's because there is no nuber that can multiply by itself to equal 6. Therefore it's not a perfct square. Any number that is not a perfect square is automatically irational.

a rational number is a number which can be expressed as a ratio of two integers

A -1/1 = -1

B 0/2 = 0

C 1/7

D sqr rt of 6..no ratio of 2 integers.<<<

sq rt 6

sq rt are not rational unless they are perfect sq rt.