Question 99024
Yes 20 miles is the correct answer. You should have used the Pythagorean theorem {{{a^2+b^2=c^2}}}to solve this problem. The variable a is used to represent the distance traveled by the north bound car, so the a=15. The b variable is the unknown distance traveled by the east bound car, so b=x. Finally the c variable is the distance between the two cars which is given to be 5 more miles than the distance traveled by the east bound car, so c= x+5.
Now we can plug in these values to the Pythagorean formula and solve for x. Here is how it works out.


{{{15^2+x^2=(x+5)^2}}}
{{{225+x^2=(x+5)(x+5)}}}
{{{225+x^2=x^2+5x+5x+25}}}
{{{225+x^2=x^2+10x+25}}}
{{{200=10x}}}
{{{20=x}}}