Toán cho a/b chứng minh 5a 5a+3b / 5c + 3d = 5a – 3b / 5c – 3d 27/09/2021 By Adalyn cho a/b chứng minh 5a 5a+3b / 5c + 3d = 5a – 3b / 5c – 3d
\[\begin{array}{l} \frac{a}{b} = \frac{c}{d} \Rightarrow \frac{a}{c} = \frac{b}{d}\\ \Rightarrow \frac{{5a}}{{5c}} = \frac{{3b}}{{3d}}\\ Ap\,\,dung\,\,tinh\,\,chat\,\,cua\,\,day\,\,ti\,\,so\,\,bang\,\,nhau\,\,ta\,\,co:\\ \frac{a}{c} = \frac{b}{d} = \frac{{5a}}{{5c}} = \frac{{3b}}{{3d}} = \frac{{5a + 3b}}{{5c + 3d}} = \frac{{5a – 3b}}{{5c – 3d}}. \end{array}\] Trả lời
\[\begin{array}{l}
\frac{a}{b} = \frac{c}{d} \Rightarrow \frac{a}{c} = \frac{b}{d}\\
\Rightarrow \frac{{5a}}{{5c}} = \frac{{3b}}{{3d}}\\
Ap\,\,dung\,\,tinh\,\,chat\,\,cua\,\,day\,\,ti\,\,so\,\,bang\,\,nhau\,\,ta\,\,co:\\
\frac{a}{c} = \frac{b}{d} = \frac{{5a}}{{5c}} = \frac{{3b}}{{3d}} = \frac{{5a + 3b}}{{5c + 3d}} = \frac{{5a – 3b}}{{5c – 3d}}.
\end{array}\]