For natural numbers m,n if (1-y)^m (1+y)^n = 1+ay+by^2 +..... and a=b= 10, then (m,n) is ?

Question

priyar · Answer

@Jaynator495  @jigglypuff314  @TheSmartOne  @Luigi0210 @robtobey @agent0smith

priyar · Answer

i got 2 eqs nC1-mC1 = 10 and nC2 +mC2 = 10 ...are these correct?

imqwerty · Answer

$\left[~^mC_0(-y)^0 +~^mC_1(-y)^1+....~^mC_m(-y)^m \right] \left[~^nC_0(y)^0+~^nC_1y^1+...+~^nC_n(y)^n\right]$ 

you will get the term of format ay only when you multiply something like-> 1 \times y 
make such cases and then add al cases where ay thing is forming
same for by^2

priyar · Answer

ya i did like this for the first two terms and got the abv.. 2 eqs are they correct?

imqwerty · Answer

i am checking the 2nd one
1st one is correct

priyar · Answer

ok..

priyar · Answer

@imqwerty?

imqwerty · Answer

sorry there was some network error..

priyar · Answer

oh..its ok

imqwerty · Answer

okay the 2nd equation  is not correct

you can get a y^2 term on multiplying 2 y terms

priyar · Answer

oh ok...got it!

imqwerty · Answer

:)

priyar · Answer

Thanks!

priyar · Answer

can you help in the other one also?