Question 1137744


{{{(x + y)^13 =13C0*x^13*y^0+13C1*x^12*y^1+13C2*x^11*y^2}}}+{{{13C3 (x)^10*(y)^3+13C4 (x)^9*(y)^4}}}...

=>{{{13C4 (x)^9*y^4=715x^9*y^4}}}


the coefficient of {{{x^9* y^4}}} in the binomial expansion of {{{(x + y)^13 }}}power is {{{715}}}