Substitute the given values of a and b into the expression:
[tex]ab-3a[/tex]If a=-4 and b=-2, then:
[tex]ab-3a=(-4)(-2)-3(-4)[/tex]Use the order of operations to simplify the arithmetic expression:
[tex]\begin{gathered} (-4)(-2)-3(-4)=8-3(-4) \\ =8+12 \\ =20 \end{gathered}[/tex]Therefore, the value of ab-3a if a=-4 and b=-2, is:
[tex]20[/tex]