第3个回答 2020-09-16
0.43×0.3+0.9×4.34+0.007×43.4
=0.129+(1-0.1)×4.34+(0.01-0.003)×43.4
=0.129+1×4.34-0.1×4.34+0.01×43.4-0.003×43.4
=0.129+4.34-0.434+0.434-0.1302
=(0.129+4.34-0.1302)+(0.434-0.434)
=0.129+4.34-0.129-0.0012
=(4.34-0.0012)+(0.129-0.129)
=4.3388