document.write( "Question 1199000: Solve for x the inequality equation (x+9)/(x+1) -2 > 0\r
\n" ); document.write( "\n" ); document.write( "The correct answer is one of the following. Which one is correct?\r
\n" ); document.write( "\n" ); document.write( "A) -1 < x < 7\r
\n" ); document.write( "\n" ); document.write( "B) x > 7\r
\n" ); document.write( "\n" ); document.write( "C) -1 < x < 8\r
\n" ); document.write( "\n" ); document.write( "D) x > 8
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Algebra.Com's Answer #832688 by greenestamps(13200)\"\" \"About 
You can put this solution on YOUR website!


\n" ); document.write( "Given the answer choices, by far the quickest path to the answer is to see which one works. From the given answer choices, the x values -1, 7, and 8 need to be the endpoints of the solution interval(s) -- which means the value of the expression is either 0 or undefined at those values.

\n" ); document.write( "The expression is undefined at x=-1 and 0 at x=7; it is neither 0 nor undefined at x=8. Since the inequality is a strict inequality (endpoints of the intervals not included), the solution set is either (-1,7) or (-infinity,-1) U (7,infinity). But that second possibility is not one of the answer choices, so

\n" ); document.write( "ANSWER: A) (-1,7)

\n" ); document.write( "But surely the intended purpose of the problem was for you to learn how to get that answer....

\n" ); document.write( "Keep everything on one side of the inequality, with \"0\" on the other side; and combine the terms on the left with a common denominator so the expression is a rational function.

\n" ); document.write( "\"%28x%2B9%29%2F%28x%2B1%29+-2+%3E+0\"

\n" ); document.write( "\"%28x%2B9%29%2F%28x%2B1%29-%282%28x%2B1%29%29%2F%28x%2B1%29+%3E+0\"

\n" ); document.write( "\"%28x%2B9-2x-2%29%2F%28x%2B1%29+%3E+0\"

\n" ); document.write( "\"%28-x%2B7%29%2F%28x%2B1%29+%3E+0\"

\n" ); document.write( "That rational function is equal to 0 at x = 7 and is undefined at x = -1, so those are endpoints of the interval(s) of the solution set. And evaluating the expression at x = 0 shows the inequality is satisfied, so the solution set is (-1,7).

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