Valor que hace equivalente la ecuación

\[4x + 12 = 40\]

\[3(m - 8) = 6(m + 2) \]

\[2(a + 8) = 40 - a\]

\[3n - 5 = 4 + n\]

\[2(3x - 7) = 4x - 6\]

\[4(b - 9) = -16\]

\[4(y - 2) = 12 - y\]