To solve the equation \((7 \times 3) / 4 = ? / 4\), we first calculate \(7 \times 3\):
\[ 7 \times 3 = 21 \]
Now we can substitute this into the equation:
\[ \frac{21}{4} = \frac{?}{4} \]
Since both sides have the same denominator (4), we can set the numerators equal to each other:
\[ ? = 21 \]
So the answer is:
\[ ? = 21 \]