question_answer

For natural numbers m, n if \[{{(1-y)}^{m}}{{(1+y)}^{n}}\] \[=1+{{a}_{1}}y+{{a}_{2}}{{y}^{2}}+...\]and \[{{a}_{1}}={{a}_{2}}=10,\] then \[(m+n)\] is

Answer:

(80)