Question

Given: x + 2y = -6.
Solve for x.

What is the coefficient of y?

Answer 1

\[ x = -6 - 2y, \]so the coefficient is -2.

Answer 2

To solve for x, you need to see what is happening to x.
All I see is 2y being added to x.
In order to undo an addition, you must subtract.
The rule is that you must do the same to both sides of an equation, so subtract 2y from both sides of the equation.