document.write( "Question 1165717: Rachel and Mari is a student athlete, they have played for Manila Meet, Palarong
\n" ); document.write( "Pambansa and represented our school in UAAP. So far, Rachel has won 24 out of 40
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\n" ); document.write( "a. Write a rational equation for the given
\n" ); document.write( "b. How many matches will Rachel have to win in a row to improve her winning percentage
\n" ); document.write( "to 75 %?
\n" ); document.write( "c. How many matches will Rachel have to win in a row to improve her winning percentage
\n" ); document.write( "to 90%?
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Algebra.Com's Answer #790181 by Theo(13342)\"\" \"About 
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so far rachel has won 24 out of 40.
\n" ); document.write( "her winning percentage is 24 / 40 * 100 = 60%.\r
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\n" ); document.write( "\n" ); document.write( "let y equal the percent of matches she has won.
\n" ); document.write( "let x = the number of matches she has to to win.\r
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\n" ); document.write( "\n" ); document.write( "when x = 40, the number of wins is 24 for a percentage of wins of 24/40 = .6 * 100 = 60%.\r
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\n" ); document.write( "\n" ); document.write( "our equation will be y = x / (x + 16) * 100.\r
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\n" ); document.write( "\n" ); document.write( "y represents the percent of games won.
\n" ); document.write( "x represents the number of games won
\n" ); document.write( "x + 16 represents the number of games played.
\n" ); document.write( "x/(x+16) represents the ratio of games won.
\n" ); document.write( "x/(x+16) represents the percent of games won.\r
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\n" ); document.write( "\n" ); document.write( "since rachel has to win every additional match she plays, the number of wins and the number of games played increments by 1 every time x increments by 1.\r
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\n" ); document.write( "\n" ); document.write( "when y = 60, the equation becomes:
\n" ); document.write( "60 = x / (x + 16) * 100
\n" ); document.write( "multiply both sides of this equation by (x + 16) to get:
\n" ); document.write( "60 * (x + 16) = 100 * x
\n" ); document.write( "factor the left side of this equation to get:
\n" ); document.write( "60 * x + 60 * 16 = 100 * x
\n" ); document.write( "subtract 60 * x from both sides of this equation to get:
\n" ); document.write( "60 * 16 = 100 * x - 60 * x
\n" ); document.write( "simplify to get:
\n" ); document.write( "960 = 40 * x
\n" ); document.write( "solve for x to get:
\n" ); document.write( "x = 960 / 40 = 24.\r
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\n" ); document.write( "\n" ); document.write( "when x = 24, she has won 24 games out of a total of 40 games for a winning percentage of 24/40 * 100 = 60%.\r
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\n" ); document.write( "\n" ); document.write( "when y = 75, the equation becomes:
\n" ); document.write( "75 = x / (x + 16) * 100
\n" ); document.write( "multiply both sides of this equation by (x + 16) to get:
\n" ); document.write( "75 * (x + 16) = 100 * x
\n" ); document.write( "simplify to get:
\n" ); document.write( "75 * x + 16 * 75 = 100 * x
\n" ); document.write( "subtract 75 * x from both sides of the equation and simplify to get:
\n" ); document.write( "1200 = 25 * x
\n" ); document.write( "solve for x to get:
\n" ); document.write( "x = 1200 / 25 = 48\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "when x = 48, she has won 48 games out of a total of 64 games for a winning percentage of 48/64 * 100 = 75%.\r
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\n" ); document.write( "\n" ); document.write( "when y = 90, the equation becomes:
\n" ); document.write( "90 = x / (x + 16) * 100
\n" ); document.write( "multiply both sides of this equation by (x + 16) to get:
\n" ); document.write( "90 * (x + 16) = 100 * x
\n" ); document.write( "simplify to get:
\n" ); document.write( "90 * x + 1440 = 100 * x
\n" ); document.write( "subtract 90 * x from both sides of the equation to get:
\n" ); document.write( "1440 = 10 * x
\n" ); document.write( "solve for x to get:
\n" ); document.write( "x = 144\r
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\n" ); document.write( "\n" ); document.write( "when x = 144, she has won 144 games out of 160 for a winning percentage of 144 / 160 * 100 = 90%.\r
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\n" ); document.write( "\n" ); document.write( "the equation can be graphed.
\n" ); document.write( "it looks like this:\r
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