Question

Câu 7. Tính bằng cách thuận tiện nhất:
2\5 x 51 + 2\5 + 2\5 x 48

Answer 1

Ta có:

\(\frac{2}{5}\text{x}51+\frac{2}{5}+\frac{2}{5}\text{x}48\)

\(=\frac{2}{5}\text{x}51+\frac{2}{5}\text{x}1+\frac{2}{5}\text{x}48\)

\(=\frac{2}{5}\left(51+1+48\right)\)

\(=\frac{2}{5}\text{x}100\)

\(=0,4\text{x}100\)

\(=40\)