Question

Aflati numerele naturale a si b stiind ca a/b =(echivalent) 7/8 si 3×a-b=169 Repede pls!​

Answer 1

$\it \left.\begin{aligned} \it \dfrac{a}{b}=\dfrac{7}{8}\ \Rightarrow b=\dfrac{8a}{7}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \\ \\ \\ \it 3a-b=169 \Rightarrow b=3a-169 \end{aligned}\right\}\ \Rightarrow 3a-169=\dfrac{8a}{7}\Big|_{\cdot7} \Rightarrow 21a-7\cdot169=8a \Rightarrow \\ \\ \\ \ \Rightarrow 21a-8a=7\cdot169\ \Rightarrow 13a=7\cdot169\Big|_{:13}\ \Rightarrow a=7\cdot13\ \Rightarrow a=91\\ \\ \\ b=\dfrac{8a}{7}=\dfrac{8\cdot91}{7}=8\cdot13\ \Rightarrow b=104$