document.write( "Question 456643: please help, I am lost\r
\n" ); document.write( "\n" ); document.write( "A car travels 150 mi at a certain speed, fi the speed has been 5mph faster, the trip would have been made in 1 hr. less time find the speed. \n" ); document.write( "
Algebra.Com's Answer #313364 by mananth(16946)\"\" \"About 
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let the original speed = x
\n" ); document.write( "increased speed = x+5
\n" ); document.write( "t=d/r
\n" ); document.write( "original time - time with increased speed = 1\r
\n" ); document.write( "\n" ); document.write( "150/x -150/(x+5)=1
\n" ); document.write( "x(x+5) is the LCD\r
\n" ); document.write( "\n" ); document.write( "150(x+5)-150x= x(x+5)\r
\n" ); document.write( "\n" ); document.write( "150x+750-150x=x^2+5x
\n" ); document.write( "x^2+5x-750=0\r
\n" ); document.write( "\n" ); document.write( "Find the roots of the equation by quadratic formula
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\n" ); document.write( "a= 1 ,b= 5 ,c= -750
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\n" ); document.write( "b^2-4ac= 25 - 3000
\n" ); document.write( "b^2-4ac= 3025
\n" ); document.write( "\"sqrt%28%093025%09%29\"= 55
\n" ); document.write( "\"x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29\"
\n" ); document.write( "\"x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29\"
\n" ); document.write( "x1=( -5 + 55 )/ 2
\n" ); document.write( "x1= 25
\n" ); document.write( "x2=( -5 -55 ) / 2
\n" ); document.write( "x2= -30
\n" ); document.write( "Ignore negative value
\n" ); document.write( "speed = 25 mph
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