Step-by-step explanation: When you're asked to solve for <em>x</em> in an equation, what you're really being asked to do is get <em>x</em> by itself on one side of the equation.
In this problem since 4 is being added to <em>x</em>, in order to get <em>x</em> by itself, we must subtract 4 from the left side of the equation and when we subtract 4 from the left side of the equation, remember that we must also subtract 4 from the right side of the equation.
