Consider the first equation. Variable $x$ cannot be equal to $\frac{4}{3}$ since division by zero is not defined. Multiply both sides of the equation by $3x-4$.
$$1=5\left(3x-4\right)$$
Use the distributive property to multiply $5$ by $3x-4$.
$$1=15x-20$$
Swap sides so that all variable terms are on the left hand side.
$$15x-20=1$$
Add $20$ to both sides.
$$15x=1+20$$
Add $1$ and $20$ to get $21$.
$$15x=21$$
Divide both sides by $15$.
$$x=\frac{21}{15}$$
Reduce the fraction $\frac{21}{15}$ to lowest terms by extracting and canceling out $3$.