To find an equation equivalent to \(2x + 3y = 5\) by multiplying the entire equation by 4, you would perform the following calculation:
\[ 4(2x + 3y) = 4(5) \]
This simplifies to:
\[ 8x + 12y = 20 \]
Thus, the equation \(2x + 3y = 5\) is equivalent to \(8x + 12y = 20\) after multiplying by 4.