решите уравнение
[m]\frac{5x+7}{x+3}-4=0[/m] [m]\frac{5x+7}{x+3}-4\cdot \frac{x+3}{x+3}=0[/m] [m]\frac{5x+7-4(x+3)}{x+3}=0[/m] [m]\frac{5x+7-4x-12}{x+3}=0[/m] [m]\frac{x-5}{x+3}=0[/m] [m]\left\{\begin {matrix}x-5=0\\x+3 ≠ 0\end {matrix}\right.[/m] x=5 О т в е т. х=5