document.write( "Question 207220: I need assistance with two separate word problems.\r
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document.write( "1) A car radiator contains 10 liters of a 30% solution. How many liters will have to be replaced with pure antifreeze if the resulting solution is to be 50% antifreeze?\r
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document.write( "2) You are planning to start a business that will require an investment of $90,000. You have found some people who are willing to share equally in the venture. If you find three more people, each person's share will decrease by $2500. how many people have you found so far?\r
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document.write( "Thank you immensely, \r
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document.write( "Andrew
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Algebra.Com's Answer #156755 by ankor@dixie-net.com(22740) You can put this solution on YOUR website! 1) A car radiator contains 10 liters of a 30% solution. \n" ); document.write( " How many liters will have to be replaced with pure antifreeze if the resulting \n" ); document.write( " solution is to be 50% antifreeze? \n" ); document.write( ": \n" ); document.write( "let x = amt of pure antifreeze to be added \n" ); document.write( "and also \n" ); document.write( "let x = amt of 30% solution to be removed \n" ); document.write( ": \n" ); document.write( ".30(10-x) + x = .50(10) \n" ); document.write( ": \n" ); document.write( "3 - .3x + x = 5 \n" ); document.write( ": \n" ); document.write( "-.3x + 1x = 5 - 3 \n" ); document.write( ": \n" ); document.write( ".7x = 2 \n" ); document.write( "x = \n" ); document.write( "x = 2.857 liters of 30% solution replaced by pure antifreeze \n" ); document.write( ": \n" ); document.write( "Check solution: \n" ); document.write( ".30(10-2.857) + 2.857 = .50(10) \n" ); document.write( "2.143 + 2.857 = 5 \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "2) You are planning to start a business that will require an investment of $90,000. \n" ); document.write( "You have found some people who are willing to share equally in the venture. \n" ); document.write( " If you find three more people, each person's share will decrease by $2500. \n" ); document.write( " how many people have you found so far? \n" ); document.write( ": \n" ); document.write( "Let x = no. of people so far: \n" ); document.write( "then \n" ); document.write( "(x+3) = no. of people to decrease share by $2500 \n" ); document.write( ": \n" ); document.write( "Original share amt = Three more share amt + $2500 \n" ); document.write( " \n" ); document.write( "Multiply equation x(x+3); results \n" ); document.write( "90000(x+3) = 90000x + 2500x(x+3) \n" ); document.write( ": \n" ); document.write( "90000x + 270000 = 90000x + 2500x^2 + 7500x \n" ); document.write( ": \n" ); document.write( "Arrange on the right: \n" ); document.write( "0 = 90000x - 90000x + 2500x^2 + 7500x - 270000 \n" ); document.write( ": \n" ); document.write( "A quadratic equation: \n" ); document.write( "2500x^2 + 7500x - 270000 = 0 \n" ); document.write( ": \n" ); document.write( "Simplify, divide by 2500 \n" ); document.write( "x^2 + 3x - 108 = 0 \n" ); document.write( ": \n" ); document.write( "Factors to: \n" ); document.write( "(x+12)(x-9) = 0 \n" ); document.write( "Positive solution \n" ); document.write( "x = 9 people originally \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Check solution: \n" ); document.write( "90000/9 = 10000 \n" ); document.write( "90000/12 = 7500 \n" ); document.write( "---------------- \n" ); document.write( "difference 2500 \n" ); document.write( " |