How might the fact that multiple approaches yield the same result contribute to the development of a theory? The accumulation of information from multiple approaches provides ample evidence to support the theory.
Scientists are more likely to develop a theory for a concept that is a popular area of research.
Evidence from multiple approaches might prevent a poorly developed theory from being accepted.
The number of observations from multiple approaches usually exceeds the number that is required.

the answer is the

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-

answerlinnaeus;