Question

4.9×8.6+0.86×49简算？

不知道是不是打印错了

Answer 1

4.9×8.6+0.86×49
=4.9×8.6+8.6×4.9
=8.6×(4.9+4.9)
=8.6×9.8
=8.6×(10-0.2)
=8.6×10-8.6×0.2
=86-17.2
=68.8

Answer 2

4.9x8.6=4.9x0.86x10=49x0.86
49x0.86+0.86x49=49x2x0.86=98x0.86=100x0.86-2x0.86=86-1.72=84.28