2.4×8.7-4.7×2.4﹢2.1
=2.4×﹙8.7-4.7)﹢2.1
=2.4×4+2.1
=11.7
第二题有错:“15分之14-15分之6乘以7”根本减不了,14/15—42/15(只有可能是负数),请检查一下题目.
10.25-1/6×13-5÷6
=10.25-13/6-5/6
=10.25-(13/6+5/6)
=10.25-3
=7.25
5/8×(1÷3/5-3/5÷1)+1/3
=5/8×(5/3-3/5)+1/3
=5/8×5/3-5/8×3/5+1/3
=25/24-3/8+1/3
=24
如有漏洞请指出,