Răspuns
Explicație pas cu pas:
Se aplica "metoda k" :
[tex]\dfrac{a}{b}=\dfrac{3}{11}=k\Rightarrow \dfrac{a}{3}=\dfrac{b}{11}=k\Rightarrow a=3k,b=11k\\\\\dfrac{7a-2b}{2a+3b}=\dfrac{7\cdot 3k-2\cdot 11k}{2\cdot 3k+3\cdot 11k}=\dfrac{21k-22k}{6k+33k} =\dfrac{-k}{39k}=-\dfrac{1}{39}[/tex]