Question

Tính nhanh 198 × 78 + 198 × 21 + 198

Answer 1

198 × 78 + 198 × 21 + 198= 198 × 78 + 198 × 21 + 198 x 1

= 198 x ( 78 + 21 +1 )

= 198 x 100 

= 19800

Answer 2

198x78+198x21+198

=198x(78+21)

=198x99

=19602

 

Answer 3

198 x 78 + 198 x 21 + 198 

= 198 x ( 78 + 21 + 1 ) 

= 198 x 100

= 19800