Question

Tính hợp lý :

a. 47. 69 - 31. ( -47 )

Answer 1

\(=47.69-31.47.\left(-1\right)\\ =47.\left(69+31\right)\\ =47.100=4700\)

Answer 2

\(47\cdot69-31\cdot(-47)\\=47\cdot69-31\cdot(-1)\cdot47\\=47\cdot69+31\cdot47\\=47\cdot(69+31)\\=47\cdot100\\=4700\)

Answer 3

=47.69−31.47.(−1)

=47.(69+31)

=47.100

=4700

Tick mik nha :D