Yes.
2/3 is rational. Rational numbers are numbers that can be written as a fraction. Irrational numbers cannot be expressed as a fraction.
It would be 21 and two thirds, so it can be expressed as a fraction and is therefore rational.
Every time. The sum of two rational numbers MUST be a rational number.
It must be a generalised rational number. Otherwise, if you select a rational number to multiply, then you will only prove it for that number.
Yes.
No. It's the ratio of -17 and 3 ... a perfectly rational number.
It's rational
2/3 is rational. Rational numbers are numbers that can be written as a fraction. Irrational numbers cannot be expressed as a fraction.
A rational number.
Yes because any number that can be expressed as a fraction is a rational number
Yes.
A rational number is one which can be expressed as one integer over another (possibly the same) integer which is not zero. thirty thirds = 30/3 which is one integer over another integer → it is rational.
It would be 21 and two thirds, so it can be expressed as a fraction and is therefore rational.
2 and 2/3 is the mixed number for two and two thirds.
30 / 3 = 10 10 is an integer, so of course it is rational! Any number that can be exactly expressed as a ratio is by definition rational.
The product of two rational numbers is always a rational number.