Variable $x$ cannot be equal to $\frac{14}{3}$ since division by zero is not defined. Multiply both sides of the equation by $8\left(3x-14\right)$, the least common multiple of $14-3x,8$.
$$-8\left(7-x\right)=5\left(3x-14\right)$$
Use the distributive property to multiply $-8$ by $7-x$.
$$-56+8x=5\left(3x-14\right)$$
Use the distributive property to multiply $5$ by $3x-14$.