document.write( "Question 169103: A 135-kg steer gains 3.5kg/day and costs 80 cents /day to keep. The market price for beef cattle is $1.65/kg, but the price falls by 1 cent /day. When should the steer be sold to maximize profit ?
\n" ); document.write( "I tried to make the profit equation for this problem but got confused when I tried to make the cost part of it , how do I make the profit equation? \n" ); document.write( "
Algebra.Com's Answer #124706 by scott8148(6628)\"\" \"About 
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the selling price of a steer in x days is the weight (135+3.5x) times the unit price (1.65-.01x)\r
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\n" ); document.write( "\n" ); document.write( "the cost to keep the steer for x days is .8x\r
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\n" ); document.write( "\n" ); document.write( "the profit is the selling price minus the cost __ (135+3.5x)(1.65-.01x)-.8x __ this is the function to maximize\r
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\n" ); document.write( "\n" ); document.write( "FOILing __ 222.75+5.775x-1.35x-.035x^2-.8x = p __ -.035x^2+3.625x+222.75 = p\r
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\n" ); document.write( "\n" ); document.write( "the maximim is on the axis of symmetry __ the general eqn is x=-b/(2a)
\n" ); document.write( "__ in this case __ x=-3.625/[2(-.035)] __ x=51.8 (approx)\r
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\n" ); document.write( "\n" ); document.write( "the steer should be sold on the 52nd day to maximize profit \n" ); document.write( "
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