document.write( "Question 1194429: The numerator of the fraction is x, while the denominator is 5 more the numerator if the value of the fraction is less than 2/5, find the value of x \n" ); document.write( "
Algebra.Com's Answer #826629 by math_tutor2020(3817)\"\" \"About 
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\n" ); document.write( "x = numerator
\n" ); document.write( "x+5 = denominator\r
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\n" ); document.write( "\n" ); document.write( "x/(x+5) is the fraction itself
\n" ); document.write( "It is stated to be less than 2/5\r
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\n" ); document.write( "\n" ); document.write( "x/(x+5) < 2/5\r
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\n" ); document.write( "\n" ); document.write( "Notice that x = -5 leads to a division by zero error.
\n" ); document.write( "This is a natural cutting point to divide the x axis number line into two pieces, and we'll test each piece.\r
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\n" ); document.write( "\n" ); document.write( "Let's plug in something to the left of x = -5, let's say x = -6
\n" ); document.write( "So,
\n" ); document.write( "x/(x+5) < 2/5
\n" ); document.write( "-6/(-6+5) < 2/5
\n" ); document.write( "6 < 2/5
\n" ); document.write( "6 < 0.4
\n" ); document.write( "which is clearly false
\n" ); document.write( "You'll find a false statement results when you plug in anything to the left of x = -5
\n" ); document.write( "So we ignore x < -5 and x = -5 itself.\r
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\n" ); document.write( "\n" ); document.write( "Let's try something to the right of x = -5. I'll try x = 0
\n" ); document.write( "x/(x+5) < 2/5
\n" ); document.write( "0/(0+5) < 2/5
\n" ); document.write( "0 < 2/5
\n" ); document.write( "0 < 0.4
\n" ); document.write( "That is true. This suggests that x > -5 is the solution set.\r
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\n" ); document.write( "\n" ); document.write( "However, we need to solve for x like so
\n" ); document.write( "x/(x+5) < 2/5
\n" ); document.write( "5x < 2(x+5)
\n" ); document.write( "5x < 2x+10
\n" ); document.write( "5x-2x < 10
\n" ); document.write( "3x < 10
\n" ); document.write( "x < 10/3
\n" ); document.write( "The inequality sign stays the same the entire time. It only flips if we were to multiply or divide both sides by a negative number.\r
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\n" ); document.write( "\n" ); document.write( "The reality is that yes x > -5 must be the case, but we also need x < 10/3 as well
\n" ); document.write( "Put together, the solution set is -5 < x < 10/3\r
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\n" ); document.write( "\n" ); document.write( "A quick way to verify this is to graph these equations
\n" ); document.write( "y = x/(x+5)
\n" ); document.write( "y = 2/5
\n" ); document.write( "Then notice how the hyperbolic curve is below the horizontal line along the interval -5 < x < 10/3\r
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\n" ); document.write( "\n" ); document.write( "Graph:
\n" ); document.write( "https://www.desmos.com/calculator/fmus5i4ao0
\n" ); document.write( "Desmos is a free graphing app.
\n" ); document.write( "You can click on the intersection of the horizontal line and the curve to see the coordinates of said intersection point.
\n" ); document.write( "Keep in mind that 10/3 = 3.333 approximately.\r
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\n" ); document.write( "\n" ); document.write( "Answer: Anything on the interval -5 < x < 10/3
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