document.write( "Question 1120318: 2/x+1 < 4/4x-2 Fractional Inequality \n" ); document.write( "
Algebra.Com's Answer #735978 by greenestamps(13209)\"\" \"About 
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\n" ); document.write( "Presumably the inequality is

\n" ); document.write( "\"2%2F%28x%2B1%29%3C4%2F%284x-2%29\" or \"2%2F%28x%2B1%29%3C2%2F%282x-1%29\"

\n" ); document.write( "Rewrite the inequality with \"0\" on one side and do a sign analysis on the resulting expression.

\n" ); document.write( "\"2%2F%28x%2B1%29-2%2F%282x-1%29+%3C+0\"
\n" ); document.write( "\"%282%282x-1%29-2%28x%2B1%29%29%2F%28%28x%2B1%29%282x-1%29%29+%3C+0\"
\n" ); document.write( "\"%284x-2-2x-2%29%2F%28%28x%2B1%29%282x-1%29%29+%3C+0\"
\n" ); document.write( "\"%282x-4%29%2F%28%28x%2B1%29%282x-1%29%29+%3C+0\"
\n" ); document.write( "\"%28x-2%29%2F%28%28x%2B1%29%282x-1%29%29+%3C+0\"

\n" ); document.write( "The expression is equal to 0 at x = 2; it is undefined at x = -1 and x = 1/2.

\n" ); document.write( "The expression is positive for large positive values of x, because all the factors will be positive.

\n" ); document.write( "As we \"walk\" along the number line, the sign of the expression changes each time we pass a point where the numerator or denominator is zero -- i.e., where the expression is either zero or undefined. So

\n" ); document.write( "The expression is zero or positive (the inequality is not true) on the interval [2, infinity);
\n" ); document.write( "The expression is negative (the inequality is true) on the interval (1/2,2);
\n" ); document.write( "The expression is again positive (the inequality is not true) on the interval (-1,1/2); and
\n" ); document.write( "The expression is again positive (the inequality is true) on the interval (-infinity, -1)

\n" ); document.write( "Answer: The solution set for the inequality is (-infinity,-1) union (1/2,2)

\n" ); document.write( "The solution can be verified with a graph of 2/(x+1) (red) and 2/(2x-1) (green):

\n" ); document.write( "\"graph%28400%2C400%2C-3%2C3%2C-10%2C10%2C2%2F%28x%2B1%29%2C2%2F%282x-1%29%29\"
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