Simplify the given algebraic expression. \[ 6(9 y-3)-(3 y+9) \] \[ 6(9 y-3)-(3 y+9)= \]

Step 1 ：Distribute the 6 to both terms inside the first parentheses: \(6 * 9y - 6 * 3\)

Step 2 ：Distribute the negative sign to both terms inside the second parentheses: \(-1 * 3y - 1 * 9\)

Step 3 ：Combine like terms to simplify the expression: \(54y - 18 - 3y + 9\)

Step 4 ：Final Answer: \(\boxed{51y - 27}\)