document.write( "Question 919259: The manager of a large apartment complex has found that the profit is given by P(x)=-x^2+720x-14000,
\n" ); document.write( "where x is the number of apartments rented. For what values of X does the complex produce a profit\r
\n" ); document.write( "\n" ); document.write( "Ive been stuck on this forever and I need help. I have a test coming up soon and I dont know how to do this type of problem \n" ); document.write( "
Algebra.Com's Answer #557624 by ewatrrr(24785)\"\" \"About 
You can put this solution on YOUR website!
Format ax^2 + bx + c
\n" ); document.write( "the vertex form of a Parabola opening up(a>0) or down(a<0), \"y=a%28x-h%29%5E2+%2Bk\"
\n" ); document.write( "P(x)=-x^2+720x-14000 |parabola opening downward: a = -1 < 0
\n" ); document.write( "complete Square
\n" ); document.write( "p(x) = -(x-360)^2 + (360)^2 - 14000 |Note 360 = 720/-2a = b/-2a
\n" ); document.write( "x = 360 is the x-value of the vertex of this parabola opening downward
\n" ); document.write( "x = b/-2a = 360, max profit
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\n" ); document.write( "\n" ); document.write( "For what values of X does the complex produce a profit
\n" ); document.write( "P(x)= -x^2+720x-14000 > 0
\n" ); document.write( "-(x-360)^2 + (360)^2 - 14000 = 0
\n" ); document.write( "(x-360)^2 = (360)^2 - 14000
\n" ); document.write( "(x-360)^2 = 115600
\n" ); document.write( "x - 360 = ± 340
\n" ); document.write( "x = 360 ± 340
\n" ); document.write( "x-intercepts are 20, 700
\n" ); document.write( "20 < x < 700 produces a profit (x = 360 being the max profit value)
\n" ); document.write( "..........
\n" ); document.write( "0r by factoring
\n" ); document.write( "-x^2+720x-14000 = 0
\n" ); document.write( "x^2-720x+14000
\n" ); document.write( "(x-20)(x-700) = 0 Same results, of course.
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