To find an equivalent equation by multiplying the given equation \(2x + 3y = 5\) by 4, you simply distribute the 4 to each term in the equation:
\[ 4(2x) + 4(3y) = 4(5) \]
Calculating each term:
\[ 8x + 12y = 20 \]
Thus, the equation \(2x + 3y = 5\) is equivalent to:
\[ 8x + 12y = 20 \]