[tex]\it \left.\begin{aligned}\it 2a = 2(a+b) \Rightarrow 2a=2a+2b|_{-2a} \Rightarrow 0=2b \Rightarrow b=0\\ \\ \it b=7\cdot100- 19\cdot9-72:8 \Rightarrow b=700-171-9=520 \end{aligned}\right\}\ 520\ne0 \Rightarrow\\ \\ \\ \Rightarrow egalitatea\ \ dat\breve a\ \ nu\ \ este\ \ adev\breve arat\breve a.[/tex]