document.write( "Question 1011333: The cost of a small bottle of juice is $y
\n" ); document.write( "the cost of a large bottle of juice is $(y+1)
\n" ); document.write( "When Jade spends $36 on small bottles only, she receives 25 more bottles than when she spends $36 on large bottles only.
\n" ); document.write( " (I) show that 25y^2+25y-36=0
\n" ); document.write( " (II) Factorise 25y^2+25y-36=0
\n" ); document.write( " (III) solve the equation 25y^2+25y-36=0
\n" ); document.write( " (IV) find the total cost of 1 small bottle of juice and 1 large bottle of juice
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Algebra.Com's Answer #626957 by Theo(13342)\"\" \"About 
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cost of a small bottle is y dollars.
\n" ); document.write( "cost of a large bottle is (y+1) dollars.\r
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\n" ); document.write( "\n" ); document.write( "\"36%2Fy\" is the number of small bottles.
\n" ); document.write( "this comes from the number of small bottle times the cost of each small bottle = 36 dollars.\r
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\n" ); document.write( "\n" ); document.write( "\"36%2F%28y%2B1%29\" is the number of large bottles.
\n" ); document.write( "this comes from the number of large bottle times the cost of each large bottle = 36 dollars.\r
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\n" ); document.write( "\n" ); document.write( "when she spends 36 dollars on small bottles, she has 25 more bottles than when she spends 36 dollars on large bottles.\r
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\n" ); document.write( "\n" ); document.write( "that leads to the equation \"36%2Fy+=+36%2F%28y%2B1%29+%2B+25\"\r
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\n" ); document.write( "\n" ); document.write( "that equation says that the number of small bottles is 25 more than the number of large bottles.\r
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\n" ); document.write( "\n" ); document.write( "you have the equation of:\r
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\n" ); document.write( "\n" ); document.write( "\"36%2Fy+=+36%2F%28y%2B1%29+%2B+25\"\r
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\n" ); document.write( "\n" ); document.write( "multiply both sides of that equation by y * (y+1) to get:\r
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\n" ); document.write( "\n" ); document.write( "\"%2836+%2A+%28y%2B1%29%29+=+%2836+%2A+y%29+%2B+%2825+%2A+%28y+%2A+%28y%2B1%29%29%29\" which becomes:\r
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\n" ); document.write( "\n" ); document.write( "\"%2836+%2A+%28y%2B1%29%29+=+%2836+%2A+y%29+%2B+%2825+%2A+%28y%5E2%2By%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "simplify to get:\r
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\n" ); document.write( "\n" ); document.write( "\"36y+%2B+36+=+36y+%2B+25y%5E2+%2B+25y\"\r
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\n" ); document.write( "\n" ); document.write( "subtract the left side of the equation from both sides of the equation to get:\r
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\n" ); document.write( "\n" ); document.write( "\"0+=+36y+%2B+25y%5E2+%2B+25y+-+36y+-+36\"\r
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\n" ); document.write( "\n" ); document.write( "the 36y and the -36y will cancel out when you combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "combine like terms to get:\r
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\n" ); document.write( "\n" ); document.write( "\"0+=+25y%5E2+%2B+25y+-+36\"\r
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\n" ); document.write( "\n" ); document.write( "that's the same as:\r
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\n" ); document.write( "\n" ); document.write( "\"25y%5E2+%2B+25y+-+36+=+0\"\r
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\n" ); document.write( "\n" ); document.write( "you would factorize 25y^2 + 25y - 36 to get:\r
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\n" ); document.write( "\n" ); document.write( "(5y+9) * (5y-4) = 0\r
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\n" ); document.write( "\n" ); document.write( "this could be done using factoring techniques or through the use of the quadratic formula.\r
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\n" ); document.write( "\n" ); document.write( "when you solve the equation of 25y^2 + 25y - 36, you set it equal to 0 and factorize it and then solve for y.\r
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\n" ); document.write( "\n" ); document.write( "each of the factors is set to 0 to solve for y.\r
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\n" ); document.write( "\n" ); document.write( "5y+9 = 0 gets you y = -9/5\r
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\n" ); document.write( "\n" ); document.write( "5y-4 = 0 gets you y = 4/5\r
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\n" ); document.write( "\n" ); document.write( "y has to be positive so y = 4/5.\r
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\n" ); document.write( "\n" ); document.write( "that's the cost of a small bottle.\r
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\n" ); document.write( "\n" ); document.write( "the cost of a large bottle would be 4/5 + 1 = 9/5.\r
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\n" ); document.write( "\n" ); document.write( "4/5 of a dollar = $0.8 dollars = 80 cents.\r
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\n" ); document.write( "\n" ); document.write( "9/5 of a dollar = $1.8 dollars = 1 dollar and 80 cents.\r
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\n" ); document.write( "\n" ); document.write( "the cost of a small bottle = 80 cents.
\n" ); document.write( "the cost of a large bottle = 1 dollar and 80 cents.\r
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\n" ); document.write( "\n" ); document.write( "36/y = number of small bottles = 36/.8 = 45 small bottles.\r
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\n" ); document.write( "\n" ); document.write( "36/(y+1) = 36/1.8 = 20 large bottles.\r
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\n" ); document.write( "\n" ); document.write( "45 small bottles is 25 more than 20 large bottles.\r
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\n" ); document.write( "\n" ); document.write( "the equation of 36/y = 36/(y+1) + 25 is good.\r
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\n" ); document.write( "\n" ); document.write( "all of the questions have been answered.\r
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\n" ); document.write( "\n" ); document.write( "1.
\n" ); document.write( "we derived 25y^2 + 25y - 36 from 36/y = 36/(y+1) + 25
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\n" ); document.write( "factors are (5y+9) * (5y-4)
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\n" ); document.write( "we got y = -9/5 and y = 4/5 where y = 4/5 was the only valid solution.
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\n" ); document.write( "the cost of a small bottle is $0.8 and the cost of a large bottle is $1.8.\r
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