900—[7.12×9.9+0.712]
=900-(7.12x9.9+7.12x0.1)
=900-7.12x(9.9+0.1)
=900-7.12x10
=900-71.2
=828.8
900—[7.12×9.9+0.712]怎样简便计算
900—[7.12×9.9+0.712]
=900-(7.12x9.9+7.12x0.1)
=900-7.12x(9.9+0.1)
=900-7.12x10
=900-71.2
=828.8