C5^0 - C5^1 + C5^2 - C5^3 + C5^4 - C5^5

Lời giải:

\(C_5^0 - C_5^1 + C_5^2 - C_5^3 + C_5^4 - C_5^5\)

= \(C_5^0{.1^5} + C_5^1{.1^4}.\left( { - 1} \right) + C_5^2{.1^3}.{\left( { - 1} \right)^2} + C_5^3{.1^2}.{\left( { - 1} \right)^3} + C_5^4.1.{\left( { - 1} \right)^4} + C_5^5.{\left( { - 1} \right)^5}\)

= [1 + (– 1)]⁵

= 0⁵ = 0.