If the expressions are equivalent we should be able to rewrite them as "-42x + 84". If we expand all the options we should find the one we need. This is done below.
1.
[tex]\begin{gathered} -3\cdot(-14x-28) \\ 42x+84 \end{gathered}[/tex]-3*(-14x) -3*(-28)
42x + 84
This one isn't equivalent, as it results in "42x + 84" which is different from what we need.
2.
[tex]\begin{gathered} 3\cdot(-14x+28) \\ -42x+84 \end{gathered}[/tex]3*(-14x) + 3*28
-42x + 84
This one is equivalent, because when expanded results in the expression we want.
3.
[tex]\begin{gathered} -14\cdot(3x\text{ - 6)} \\ -42x\text{ + }84 \end{gathered}[/tex]-14*(3x) -14*(-6)
-42*x +84
This one is equivalent, because when expanded results in the expression we want.
4.
[tex]\begin{gathered} -14\cdot(-3x\text{ - 6)} \\ 42x+84 \end{gathered}[/tex]-14*(-3x) -14*(-6)
42*x + 84
This one isn't equivalent, as it results in "42x + 84" which is different from what we need.
