42减1点4加5点77的和减8点6(能简算的要简算
问题描述：
42减1点4加5点77的和减8点6(能简算的要简算
答
42-1.4+5.77-8.6
42-(1.4+8.6)+5.77
=42-10+5.77
=32+5.77
=39.77
答
42-1.4+5.77-8.6
42-(1.4+8.6)+5.77
=42-10+5.77
=32+5.77
=39.77