Answer:
x = 2
Step-by-step explanation:
The equation shown is a perfectly good equation.
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Look at what is being done to the variable. It is multiplied by 2, and 4 is added to the product.
To find the value of the variable, we reverse these operations, in reverse order. We undo the addition by adding the opposite of 4 (to both sides of the equation).
2x +4 -4 = 8 -4
2x = 4 . . . . . simplify
We undo the multiplication by multiplying by the inverse value, 1/2 (to both sides of the equation).
(1/2)(2x) = (1/2)(4)
x = 2 . . . . . simplify
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The rules of equations are pretty simple: <em>whatever you do to one side, you must also do to the other side</em>.
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<em>Comment on this equation</em>
You may notice that all of the numbers in this equation are divisible by 2. Another way to solve it is to start by dividing (both sides!) by 2:
x + 2 = 4
Now, you have a 2nd-grade problem in addition facts: what added to 2 gives 4? Since you know your addition facts, you know the answer is 2. In algebra, we solve this by subtracting 2 (from both sides!).
x = 2
