Question

The properties of addition 3/4+1/3=1/3+3/4

Answer 1

3/4+1/3=1/3+3/4

(9+4)/12=(4+9)/122

13/12=13/12

Answer 2

I think it is Associative Property

Proof:-

$\frac{3}{4} + \frac{1}{3} =\frac{1}{3} + \frac{3}{4}$

It is coversing with two fractions