+3454 We want to solve for d. This means we want d alone on one side.
$$\begin{array}{lc}
\frac{a}{b} =\frac{c}{d}&\qquad\qquad\mbox{Multiply both sides by d}\\
\frac{a}{b}\times d=c&\qquad\qquad\mbox{Multiply both sides by b}\\
a \times d = c \times b&\qquad\qquad\mbox{Divide both sides by a}\\
d = c \times b \div a
\end{array}$$
And that's it!
+3454 We want to solve for d. This means we want d alone on one side.
$$\begin{array}{lc}
\frac{a}{b} =\frac{c}{d}&\qquad\qquad\mbox{Multiply both sides by d}\\
\frac{a}{b}\times d=c&\qquad\qquad\mbox{Multiply both sides by b}\\
a \times d = c \times b&\qquad\qquad\mbox{Divide both sides by a}\\
d = c \times b \div a
\end{array}$$
And that's it!
