12) $(6 m-3)(4 m-5)$
Final Answer: \(\boxed{24m^2 - 42m + 15}\)
Step 1 :Expand the expression: \((6m-3)(4m-5) = 6m(4m) - 6m(5) - 3(4m) + 3(5)\)
Step 2 :Combine like terms: \(24m^2 - 30m - 12m + 15 = 24m^2 - 42m + 15\)
Step 3 :Final Answer: \(\boxed{24m^2 - 42m + 15}\)