Question

Sa se dezvolte binomul la putere
$(x+y)^{7$

Answer 1

$(a+b) ^{n} =C^{0} _{n}\cdot a^{n}+C^{1} _{n}\cdot a^{n-1}\cdot b+ ......C n^{n} _{n}\cdot b^{n}.$

(x+y)⁷=x⁷+7x⁶y+21x⁵y²+35x⁴y³+35x³y⁴+21x²y⁵+7xy⁶+y⁷