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-7 + 4n = 9

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User Jian Cui
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2 Answers

2 votes

Rewrite the equation in an easier way: 4n-7=9

Add 7 to both sides: 4n-7+7=9+7... 4n=16

Divide both sides by 4: 4n/4=16/4

ANSWER: N=4


User Andrey Markeev
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7 votes

First of all, add 7 to both sides, in order to cancel the -7:


-7 + 4n +7= 9+7

As we said, the -7 on the left hand side cancels out, while we can add it to the 9 on the right hand side:


4n = 16

Now, divide both sides by 4. As before, this is needed to cancel the four on the left hand side and isolate the x, while it is just a normal division between numbers on the right:


(4n)/(4) = (16)/(4) \iff x = 4

User Dumdum
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