\(\frac{2\cdot4\cdot10+4\cdot6\cdot8+14\cdot16\cdot20}{3\cdot6\cdot15+6\cdot9\cdot12+21\cdot24\cdot30}\)
\(=\frac{8\cdot1\cdot2\cdot5+8\cdot2\cdot3\cdot4+8\cdot7\cdot8\cdot10}{27\cdot1\cdot2\cdot5+27\cdot2\cdot3\cdot4+27\cdot7\cdot8\cdot10}\)
\(=\frac{8\cdot(1\cdot2\cdot5+2\cdot3\cdot4+7\cdot8\cdot10)}{27\cdot(1\cdot2\cdot5+2\cdot3\cdot4+7\cdot8\cdot10)}=\frac{8}{27}\)
\(\frac{2.4.10+4.6.8+14.16.20}{3.6.15+6.9.12+21.24.30}\)
\(=\frac{2\left(1+2+5\right)+2\left(2+3+4\right)+2\left(7+8+10\right)}{3\left(1+2+5\right)+3\left(2+3+4\right)+3\left(7+8+10\right)}\)
\(=\frac{2\left(1+2+5+2+3+4+7+8+10\right)}{3\left(1+2+5+2+3+4+7+8+10\right)}\)
\(=\frac{2}{3}\)
Đáp án bằng \(\frac{8}{27}\)mà Nguyễn Châu Tuấn Kiệt,sao ai cũng k sai mk hết nhỉ??
