Question

Tính nhanh:

49 x 47 - 47 x 47 -30 -17

Answer 1

Tính nhanh:

49 x 47 - 47 x 47 -30 -17

= 47 x ( 49 - 47 ) - 30 - 17

= 47 x 2 - 30 - 17

= 94 - 30 - 17

= 64 - 17

= 47

nhớ k cho mình nha

Answer 2

49x47-47-30-17=47(49-1)-30-17

                         = 47x48-30-17

                          =2256-30-17=2209

Answer 3

49x47-47x30-30-17=49x47-47x47-(30+17)

=49x47-47x30-47=47x(49-47-2)=47x47=2209

Answer 4

49x47-47x47-30-17=49x47-47x47-47=47x(49-47-1)=47x1=47