Answer:
x = -2
Explanation:
First, you eliminate parentheses using the distributive property.
3(x +4) +4x = -2
3x +12 +4x = -2
Then you collect terms.
7x +12 = -2
You can subtract 12 (from both sides).
7x = -14
Finally, divide by the coefficient of the variable.
x = -14/7 = -2
The solution is x = -2.
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Comment on the work
When you add, subtract, multiply, divide, or perform any other operation on one side of the equation, you must do the same thing on the other side. That is how the equal sign stays valid. That is why we subtracted 12 from both sides of the equation. It is also why we divided both sides of the equation by 7.
Those steps, subtract 12, divide by 7, are chosen for the purpose of getting the x-term by itself, then getting by itself. In general, when there's an added term you don't want, add its opposite to both sides of the equation. When there's a factor you don't want, divide both sides of the equation by that.