If $\frac{8}{24}=\frac{4}{x+3}$, what is the value of $x$ ?
If $\frac{8}{24}=\frac{4}{x+3}$, then $8(x+3)=24(4)$ or $8 x+24=96$. Thus, $8 x=72$ and so $x=9$.

Alternatively, we could note that $\frac{8}{24}=\frac{4}{12}$ and so we have $\frac{8}{24}=\frac{4}{12}=\frac{4}{x+3}$ which gives $x+3=12$ or $x=9$.

ANSWER: 9