Proof using real number axioms and axioms of equality: a/b+c/d=ad+bc/bdShow reason in every proof
Show `a/b+c/d=(ad+bc)/(bd)` :
`a/b+c/d` is given
Since `d/d=1` and `b/b=1` by the multiplicative inverse axiom we have:
`a/b+c/d=a/b * d/d + b/b*c/d` by the multiplicative identity axiom
`=1/(bd)(ad+bc)` by the distributive axiom of mult. over addition
`=(ad+bc)/(bd)` as required.