10x+9=7x

To solve the equation \(10x + 9 = 7x\), follow these steps:

1. Subtract \(7x\) from both sides of the equation:

   \[ 10x - 7x + 9 = 7x - 7x \]

   This simplifies to:

   \[ 3x + 9 = 0 \]

2. Next, subtract \(9\) from both sides:

   \[ 3x + 9 - 9 = 0 - 9 \]

   This simplifies to:

   \[ 3x = -9 \]

3. Finally, divide both sides by \(3\) to solve for \(x\):

   \[ x = \frac{-9}{3} \]

   This gives us:

   \[ x = -3 \]

So the solution to the equation \(10x + 9 = 7x\) is \(x = -3\).