3. 3m - (7m + 12) = 2(m - 3)

Explanation:

Step1: Remove parentheses

$$3m - 7m - 12=2m - 6$$

Step2: Combine like terms

$$-4m - 12=2m - 6$$

Step3: Move terms with (m) to one side

$$-4m - 2m=-6 + 12$$

Step4: Combine like terms

$$-6m = 6$$

Step5: Solve for (m)

$$m=\frac{6}{-6}=-1$$

Answer:

(m = - 1)