Question

Tinhs bằng cách thuận tiênj nhất:                                                                       a.51x9-11x51+102                                                                                           b,{53x27-53x8+43x19} -38 x33

   

Answer 1

a) 51 x 9 - 11 x 51 + 102

= 51 x 9 - 11 x 51 + 51 x 2

= 51 x ( 9 - 11 + 2 )

= 51 x 0 = 0

b) ( 53 x 27 - 53 x 8 + 43 x 19 ) - 38 x 33

= [ 53 x ( 27 - 8 ) + 43 x 19 )] - 38 x 33

= 53 x 19 + 43 x 19 - 38 x 33

= ( 53 + 43 ) x 19 - 19 x 2 x 33

= 96 x 19 - 19 x 66

= 19 x ( 96 - 66 )

= 19 x 30 = 570

Answer 2

a. 51 x 9 - 11 x 51 + 102

= 51 x 9 - 11 x 51 + 51 x 2

= 51 x ( 9 - 11 + 2)

= 51 x 0

= 0

Answer 3

a) 51 x 9 - 11 x 51 + 102

= 51 x 9 - 11 x 51 + 51 x 2

= 51 x ( 9 - 11 + 2 )

= 51 x 0 = 0

b) ( 53 x 27 - 53 x 8 + 43 x 19 ) - 38 x 33

= [ 53 x ( 27 - 8 ) + 43 x 19 )] - 38 x 33

= 53 x 19 + 43 x 19 - 38 x 33

= ( 53 + 43 ) x 19 - 19 x 2 x 33

= 96 x 19 - 19 x 66

= 19 x ( 96 - 66 )

= 19 x 30 = 570