N:12=3:4
You asked:
Solve \(N : 12=3 : 4\) for the variable \(N\).
MathBot Answer:
$$\begin{aligned}N &= 9\end{aligned}$$
Express both ratios as fractions. \[\frac{N}{12} = \frac{3}{4}\]
Cross-multiply and solve for the unknown. $$\begin{aligned}\frac{N}{12} &= \frac{3}{4} \\ 4 N &= 36 \\ N &&= 9 \end{aligned}$$