Answer:
The second choice.
Explanation:
A rational number means that you are able to write the number as a fraction with integers in the numerator and the denominator. An integers are the whole numbers and their opposites ...-3,-2,-1,0,1,2,3...
The square root of 4 is 2. 2 can be written 2/1 (an integer over and integer)
-square root of 2 cannot be written as an integer over an integer. When this number is written as a decimal number it never repeats and it never terminates so it cannot be written as an integer over and integer.
-2/3 is written in the form of an integer over and integer.
1 can be written 1/1
9/8 is written as an integer over an integer.
The square root of 9/4 would be 3/2. (3/2)(3/2) = 9/4.
2.4 repeating can be written as an integer over an integer. Any decimal that repeats or terminates can be written as an integer over and integer. It actual happens to be 22/9.
The square root of 10 written as a decimal does not repeat or terminate so it is not rational. Only perfect squares are rational.