SOLUTION: Please help me find the value of x. {{{ 3 /(x+4) -7 = (-4) /(x+4) }}}

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Please help me find the value of x. {{{ 3 /(x+4) -7 = (-4) /(x+4) }}}      Log On


   

Question 513412: Please help me find the value of x. +3+%2F%28x%2B4%29+-7+=+%28-4%29+%2F%28x%2B4%29+
Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
+3%2F%28x%2B4%29+-7+=+-4%2F%28x%2B4%29+
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Add +%284%29%2F%28x%2B4%29+ to both sides
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+3%2F%28x%2B4%29+-7+%2B%284%29%2F%28x%2B4%29+=0+
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Add 7 to both sides
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+3%2F%28x%2B4%29+%2B%284%29%2F%28x%2B4%29+=7+
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Notice you now have a common denominator.
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+%283%2B4%29%2F%28x%2B4%29+=7+
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+7%2F%28x%2B4%29+=+7+
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Now cross multiply.
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+7+=+7%2A%28x%2B4%29+
+7+=+7x+%2B+28+
+7x+%2B+28+=+7+
+7x+=+-21+
+x+=+-3+
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Always check your answer.
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+3%2F%28-3%2B4%29+=+3%2F1+=+3+
+3+-+7+=+-4+
+-4%2F%28-3%2B4%29+=+-4+
+-4+=+-4+
Correct.
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Answer: +x=-3+
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Done.