To evaluate the expression \(4(m - n)\) when \(m = -7\) and \(n = 2\), substitute the values of \(m\) and \(n\) into the expression and perform the calculations:
\[4(-7 - 2)\]
\[4(-9)\]
\[-36\]
So, when \(m = -7\) and \(n = 2\), the value of the expression \(4(m - n)\) is \(-36\).