Question

The numerical expression 3/7+(-7)/8 =25/56 show that 1. Rational numbers are closed under addition

Answer 1

Answer:

It is proved that rational numbers are closed under addition

Step-by-step explanation:

Rule is that when adding 2rational numbers gives a rational number. i.e. meaning of rational numbers are closed under addition

From given, let a=3/7=> rational no

b=(-7/8) =>rational no

Adding c= a+b, lcm is 56

c=(24-49) /56=(-25) /56

c is also rational no

Hence proved.

note: the question is missing a "-" in equation 3/7+(-7) /8=(-25) /56

Answer 2

Answer:

Step-by-step explanation:

Given  

The numerical expression 3/7+(-7)/8 =25/56 show that 1. Rational numbers are closed under addition

ANSWER

We have to show that rational numbers are closed under addition.

So now 3/7 + (-7/8) = - 25 /56

Now both 3/7 and -7/8 are rational numbers and after addition we get – 25/56 which is also a rational number.

The sum of any two rational numbers is always a rational number.