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: whatever you do to one side, you must also do to the other side.
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Comment on this equation
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
