👤

Aflati a/b daca 3a-2b=5
5a+b=17


Răspuns :

[tex]5a+b=17 \implies \underline{b=17-5a} \\\\\\ 3a-2b=5 \\\\ 3a-2(17-5a)=5 \\\\ 3a-34+10a=5 \\\\ 13a=5+34 \\\\ 13a=39 \ \ \ |:13 \\\\ \boxed{a=3} \\\\\\ b=17-5*3 \\\\ b=17-15 \\\\ \boxed{b=2} \\\\\\ \boxed{\boxed{\frac{a}{b} \longrightarrow \frac{3}{2}}}[/tex]
[tex]\displaystyle 5a+b=17 \\ b=17-5a \\ 3a-2b=5\Rightarrow 3a-2(17-5a)=5 \Rightarrow 3a-34+10a=5 \Leftrightarrow \\ \Leftrightarrow 3a+10a=5+34 \Rightarrow 13a=39 \Rightarrow a= \frac{39}{13} \Rightarrow a= 3 \\ b=17-5a \Rightarrow b=17-5 \cdot 3 \Rightarrow b=17-15 \Rightarrow b=2 \\ \boxed{ \frac{a}{b} = \frac{3}{2} }[/tex]