<em>To solve for variables, we need the equation to be set equal to something. If no other number is given, assume zero.</em>
2x + 4 = 0
<em>Move </em><em>4</em><em> to the right by subtracting it from the left and right (since it is being added).</em>
2x = -4
<em>Next, isolate </em><em>x</em><em> by dividing both sides by </em><em>2</em><em> (since </em><em>x</em><em> is being multiplied by </em><em>2</em><em>)</em>
x = -2
<em>We can check that this is correct by plugging in </em><em>-2</em><em> for </em><em>x</em><em> and seeing if we get </em><em>zero</em><em>.</em>
