(12x+7y)+(3y-2x)

To simplify the expression \((12x + 7y) + (3y - 2x)\), you should combine like terms.

1. Start by listing all the \(x\) terms and all the \(y\) terms:

   • \(12x - 2x\) for the \(x\) terms
   • \(7y + 3y\) for the \(y\) terms

2. Now combine them:

   • \(12x - 2x = 10x\)
   • \(7y + 3y = 10y\)

3. So, the simplified expression is: \[ 10x + 10y \]

You can also factor it if needed: \[ 10(x + y) \]

Thus, the final result is: \[ 10x + 10y \quad \text{or} \quad 10(x + y) \]