yes
Yes.
yes
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. Any rational number divided by another rational number is also rational.
351 is an integer and not a fraction. However, it can be expressed in rational form as 351/1. You can then calculate equivalent rational fractions if you multiply both, its numerator and denominator, by any non-zero integer.
The number of the measured quantity is 351 grams.
It is a rational number. It can be written as a fraction.
The absolute value can be thought as the distance from 0. In other words, if you started at zero and counted to that number what number would you be on when you got there. So -351 is 351 spaces away from 0. The absolute value of -351 or |-351| is 351. Pretty easy.
yes
Is 12.05 a rational number or irrational number?
1.96 is a rational number
It is a rational number, as it can be written as a fraction.
Yes, the sum is always rational.
There is no such thing as a number that is both rational and irrational. By definition, every number is either rational or irrational.
As much as, in these days of uncertainty, anything can be anything. As long as the constraints of a rational number are kept to, a rational number will always remain a rational number.
Yes, it is.