0.386*(4.82+5.7+5.1+2.3)/3.86怎样简算?还有9*3-1.7=13.4解方程.

0.386*(4.82+5.7+5.1+2.3)/3.86
= (4.82+5.7+5.1+2.3)/10
= (4.82+5.1+5.7+2.3)/10
= (9.92+8)/10
= 17.92/10
= 1.792
9*3-1.7=13.4