b, 201 + 201 × 2 + 201 × 3 + 201 × 4
Giải thích
201 + 201 × 2 + 201 × 3 + 201 × 4
= 201 × 1 + 201 × 2 + 201 × 3 + 201 × 4
= 201 × ( 1+ 2+ 3+ 4)
= 201 × 10
= 2010
201 + 201 × 2 + 201 × 3 + 201 × 4
= 201 × 1 + 201 × 2 + 201 × 3 + 201 × 4
= 201 × ( 1+ 2+ 3+ 4)
= 201 × 10
= 2010