To find an equation equivalent to \(2x + 3y = 5\) by multiplying it by 4, simply multiply each term in the equation by 4:
\[ 4(2x) + 4(3y) = 4(5) \]
This simplifies to:
\[ 8x + 12y = 20 \]
So, the equation equivalent to \(2x + 3y = 5\) after multiplying by 4 is:
\[ 8x + 12y = 20 \]