document.write( "Question 1029152: A biker decided to cover the distance of 120 km at a certain speed. However, he actually went 6 km/h slower so he arrived at his destination 1 hour later than he wanted to. What was the actual speed of the biker?
\n" ); document.write( "PS:If x is the actual speed of the biker, then what is the equation? \n" ); document.write( "

Algebra.Com's Answer #644181 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+s+\"$ = the actual speed of the biker in km/hr
\n" ); document.write( "Let $\"+t+\"$ = the time in hrs he would normally take
\n" ); document.write( "to arrive traveling at speed $\"+s+\"$
\n" ); document.write( "--------------------------------
\n" ); document.write( "Equation for riving on time:
\n" ); document.write( "(1) $\"+120+=+s%2At+\"$
\n" ); document.write( "Equation for arriving 1 hr late:
\n" ); document.write( "(2) $\"+120+=+%28+s-6+%29%2A%28+t+%2B+1+%29+\"$
\n" ); document.write( "--------------------------
\n" ); document.write( "(1) $\"+t+=+120%2Fs+\"$
\n" ); document.write( "substitute (1) into (2)
\n" ); document.write( "(2) $\"+120+=+%28+s-6+%29%2A%28+120%2Fs+%2B+1+%29+\"$
\n" ); document.write( "(2) $\"+120+=+120+%2B+s+-+720%2Fs+-+6+\"$
\n" ); document.write( "(2) $\"+0+=+s+-+720%2Fs+-+6+\"$
\n" ); document.write( "(2) $\"+s+-+6+=+720%2Fs+\"$
\n" ); document.write( "Multiply both sides by $\"+s+\"$
\n" ); document.write( "(2) $\"+s%5E2+-+6s+=+720+\"$
\n" ); document.write( "Complete the square
\n" ); document.write( "(2) $\"+s%5E2+-+6s+%2B+%28-6%2F2%29%5E2+=+720+%2B+%28-6%2F2%29%5E2+\"$
\n" ); document.write( "(2) $\"+s%5E2+-+6s+%2B9+=+720+%2B9+\"$
\n" ); document.write( "(2) $\"+%28+s+-+3+%29%5E2+=+729+\"$
\n" ); document.write( "Take the square root of both sides
\n" ); document.write( "(2) $\"+s+-+3+=+27+\"$
\n" ); document.write( "(2) $\"+s+=+30+\"$
\n" ); document.write( "The actual speed of the biker is 30 km/hr
\n" ); document.write( "-----------------
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+120+=+s%2At+\"$
\n" ); document.write( "(1) $\"+120+=+30%2At+\"$
\n" ); document.write( "(1) $\"+t+=+4+\"$ hrs
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+120+=+%28+s-6+%29%2A%28+t+%2B+1+%29+\"$
\n" ); document.write( "(2) $\"+120+=+%28+30-6+%29%2A%28+t+%2B+1+%29+\"$
\n" ); document.write( "(2) $\"+120+=+24%2A%28+t+%2B+1+%29+\"$
\n" ); document.write( "(2) $\"+120+=+24t+%2B+24+\"$
\n" ); document.write( "(2) $\"+24t+=+96+\"$
\n" ); document.write( "(2) $\"+t+=+4+\"$ hrs
\n" ); document.write( "OK \n" ); document.write( "

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