Certainly! Here are the simplified expressions by combining like terms:
1. \(12y - 18y = -6y\)
2. \(-4(y + 5) = -4y - 20\)
3. \(3x + 6y - 9x + 4 = -6x + 6y + 4\)
4. \(6(x - 9) + 10 - 3x = 6x - 54 + 10 - 3x = 3x - 44\)
So, after combining like terms:
1. \(12y - 18y = -6y\)
2. \(-4(y + 5) = -4y - 20\)
3. \(3x + 6y - 9x + 4 = -6x + 6y + 4\)
4. \(6(x - 9) + 10 - 3x = 3x - 44\)