me ajudem por favor ???

[tex]\sf \displaystyle\frac{x-1}{3}=\frac{3}{4}\\\\\\\\\sf \frac{3\left(x-1\right)}{3}=\frac{3\cdot \:3}{4}\\\\\\\sf x-1=\frac{9}{4}\\\\\\\sf x-1+1=\frac{9}{4}+1\\\\\\\large \boxed{\sf x=\frac{13}{4} }[/tex]