192.78+192.21+8492
=192(78+21)+8492
=192.100+8492
=19200+8492
=27692
\(192\times78+192\times21+8492\)
\(=192\times\left(78+21\right)+8492\)
\(=192\times99+8492\)
\(=192\times\left(100-1\right)+8492\)
\(=192\times100-192\times1+8492\)
\(=19200-192+8492\)
\(=19200+8300\)
\(=27500\)
sr, mik nhầm tý nhé
192 x 78 + 192 x 21 + 8492 = ?
=192 x 78 +192 x 21 + 8492 x 1
= 192 x [ 78 +21 +1 ]
= 192 x100
=19200
vô máy tính mà tính
