9 a . 12x -4x =104 9b 8a+3a+4a=12 9c. 7m -3m-6 = 30 9d. 2\3y + 5\3y-8=6

9a. 12X - 4X = 104.

8X = 104,
X = 104 / 8 = 13.

9d. 2Y/3 + 5Y/3 - 8 = 6.

7Y/3 = 14,
Multiply both sides by 3:
7Y = 42,
Y = 42 / 7 = 6.

The remaining problems are similar to
9a, and 9d.