Question

Cho A=(100-40)(99-40)(98-40)...(11-40)(10-40). Hãy tính A?

Answer 1

= (100-40)...(40-40)...(10-40)

=(100-40)...0...(10-40)

= 0

 

Answer 2

\(A=\left(100-40\right)\left(99-40\right)\left(98-40\right)...\left(11-40\right)\left(10-40\right)\)

Trg A gồm có  40 -40 

⇒\(A=\left(100-40\right)\left(99-40\right)\left(98-40\right)...\left(11-40\right)\left(10-40\right).0=0\)