If , then can be determined from the equation

first by substituting 18 for :

then by dividing both sides by 18 to isolate the :

Now, in the other equation, substitute 4 for :

Divide both sides by 4 to isolate the :

,

the correct choice.

If the line of an equation passes through , then, if and , the equation should be true. Therefore, we can identify the correct choice by substituting 2 and 6 for and , respectively, in each equation.

True

True

True

True

False

The correct choice is

.

Isolate the on the left side of the equation by performing the same steps on both sides. These steps should be the opposite of the operations performed on , as follows:

Multiplication precedes subtraction in the order of operations, so reverse the subtraction of 12 by adding 12 to both sides:

Now reverse multiplication by 2 by dividing by 2:

.