document.write( "Question 1007607: a jogger ran 3 miles, decrease her speed by 1 mile per hour, and then ran another 4 miles. If her total jogging time was 1.3 hours, find her speed for the first and second part of her run. \n" ); document.write( "

Algebra.Com's Answer #623477 by lwsshak3(11628) $\"\"$ $\"About$

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a jogger ran 3 miles, decrease her speed by 1 mile per hour, and then ran another 4 miles. If her total jogging time was 1.3 hours, find her speed for the first and second part of her run.\r
\n" ); document.write( "\n" ); document.write( "let x=speed for 1st part of her run
\n" ); document.write( "x-1 =speed for 2nd part of her run
\n" ); document.write( "travel time=distance/speed
\n" ); document.write( "3/x+4/(x-1)=1.3
\n" ); document.write( "lcd:x(x-1)
\n" ); document.write( "3(x-1)+4x=1.3x^2-1.3x
\n" ); document.write( "3x-3+4x=1.3x^2-1.3x
\n" ); document.write( "1.3x^2-8.3x+3=0
\n" ); document.write( "solve for x by quadratic formula:
\n" ); document.write( " $\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"$
\n" ); document.write( "a=1.3,b=-8.3c=3c
\n" ); document.write( "x=6
\n" ); document.write( "x-1=5
\n" ); document.write( "speed for 1st part of her run=6 mph
\n" ); document.write( "speed for 2nd part of her run=5mph \n" ); document.write( "

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