Witaj :)
1]
[tex]x+\frac{1}{3}x=8\\\\1\frac{1}{3}x=8\\\\\frac{4}{3}x=8 \ \ |\cdot\frac{3}{4}\\\\x=2\cdot3\\\\\boxed{x=6}[/tex]
2]
[tex]2x+4+5x=19\\\\2x+5x=19-4\\\\7x=15 \ \ |:7\\\\x=\frac{15}{7}\\\\\boxed{x=2\frac{1}{7}}[/tex]