document.write( "Question 1032108: Katie can bicycle 69 miles in the same time as it takes her to walk 21 miles. She can ride 8 mph faster than she can walk. How fast can she walk \n" ); document.write( "

Algebra.Com's Answer #646755 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+s+\"$ = her walking speed
\n" ); document.write( " $\"+s+%2B+8+\"$ = her biking speed
\n" ); document.write( "Let $\"+t+\"$ = her time in hrs for
\n" ); document.write( "both walking and biking
\n" ); document.write( "--------------------------
\n" ); document.write( "Equation for walking:
\n" ); document.write( "(1) $\"+21+=+s%2At+\"$
\n" ); document.write( "Equation for biking:
\n" ); document.write( "(2) $\"+69+=+%28+s+%2B+8+%29%2At+\"$
\n" ); document.write( "--------------------
\n" ); document.write( "(1) $\"+t+=+21%2Fs+\"$
\n" ); document.write( "Substitute this into (2)
\n" ); document.write( "(2) $\"+69+=+%28+s+%2B+8+%29%2A%28+21%2Fs+%29+\"$
\n" ); document.write( "(2) $\"+69+=+21+%2B+168%2Fs+\"$
\n" ); document.write( "(2) $\"+48+=+168%2Fs+\"$
\n" ); document.write( "(2) $\"+s+=+168%2F48+\"$
\n" ); document.write( "(2) $\"+s+=+3.5+\"$
\n" ); document.write( "-------------------
\n" ); document.write( "Her speed walking is 3.5 mi/hr
\n" ); document.write( "-------------------
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+t+=+21%2Fs+\"$
\n" ); document.write( "(1) $\"+t+=+21%2F3.5+\"$
\n" ); document.write( "(1) $\"+t+=+6+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+69+=+%28+s+%2B+8+%29%2At+\"$
\n" ); document.write( "(2) $\"+69+=+%28+3.5+%2B+8+%29%2A6+\"$
\n" ); document.write( "(2) $\"+69+=+11.5%2A6+\"$
\n" ); document.write( "(2) $\"+69+=+69+\"$
\n" ); document.write( "OK \n" ); document.write( "

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