4.
The expression is 3x + 6.
Simplify the expression.
[tex]\begin{gathered} 3x+6=3\cdot x+3\cdot2 \\ =3(x+2) \end{gathered}[/tex]
So missing place is filled by 2.
The expression is x - 2.
Simplify the expression.
[tex]\begin{gathered} x-2=-1\cdot(-x)+(-1)\cdot2 \\ =-1(-x+2) \\ =-(2-x) \end{gathered}[/tex]
So missing place is filled by 2
The expression is (15x - 10)/5.
Simplify the expression.
[tex]\begin{gathered} \frac{15x-10}{5}=\frac{5\cdot3x-5\cdot2}{5} \\ =\frac{5(3x-2)}{5} \\ =3x-2 \end{gathered}[/tex]
So missing place is filled by 3x.
