\(\frac{4}{5}\cdot0,5+\frac{12}{5}\cdot0,3+\frac{8}{19}\cdot0,2\)
= \(\frac{4\cdot0,5}{5}+\frac{12.0,3}{5}+\frac{8\cdot0,2}{19}\)
=\(\frac{2}{5}+\frac{3,6}{5}+\frac{1,6}{19}\)
=\(\frac{2}{5}+\frac{18}{25}+\frac{8}{95}\)
=\(\frac{2\cdot475+18\cdot95+8\cdot25}{2375}\)
=\(\frac{950+1710+200}{2375}\)= \(\frac{2860}{2375}\)
Đúng ko vậy " vo minh khoa ", tính nhanh mà !