Factor 3(m-4)-n(m-4)

$3 \cdot (m - 4) - n \cdot (m - 4)$

Step 1

Factor $m - 4$ out of $3 \cdot (m - 4)$ .

$(m - 4) \cdot 3 - n \cdot (m - 4)$

Step 2

Factor $m - 4$ out of $- n \cdot (m - 4)$ .

$(m - 4) \cdot 3 + (m - 4) \cdot (- n)$

Step 3

Factor $m - 4$ out of $(m - 4) \cdot 3 + (m - 4) \cdot (- n)$ .

$(m - 4) (3 - n)$

Factor 3*(m-4)-n*(m-4)