Tính nhanh: (1 + 2 + 3 +...+ 1996) \(\large\times\) (512 \(\large\time

Tính nhanh:

(1 + 2 + 3 +...+ 1996) \(\large\times\) (512 \(\large\times\) 3 - 128 \(\large\times\) 12)

• A. 1
• B. 0
• C. 1996
• D. 2020

(1 + 2 + 3 +...+ 1996) \(\large\times\) (512 \(\large\times\) 3 - 128 \(\large\times\) 12)

= (1 + 2 + 3 +...+ 1996) \(\large\times\) (512 \(\large\times\) 3 - 128 \(\large\times\) 3 \(\large\times\) 4)

= (1 + 2 + 3 +...+ 1996) \(\large\times\) (512 \(\large\times\) 3 - 512 \(\large\times\) 3)

= (1 + 2 + 3 +...+ 1996) \(\large\times\) 0

= 0