Question 1178426


Their speeds are {{{r}}} and{{{ r-4}}}, in miles per hour.
The distance traveled for each in the {{{2}}} hours are {{{2r}}} and {{{2(r+7)}}}

We know that

{{{(2x)^2+(2(x-4))^2=42.80^2 }}}

{{{4x^2+4(x-4)^2=1831.84}}}

{{{4x^2+4(x^2-8x+16)=1831.84}}}

{{{4x^2+4x^2-32x+64=1831.84}}}

{{{8x^2-32x+64=1831.84}}}

{{{x^2-4x+8=228.98}}}

{{{x^2-4x+8-228.98=0}}}

{{{x^2-4x-220.98=0}}}.......using quadratic formula we get

{{{x}}}≈{{{-12.9993}}}->disregard negative solution

{{{x}}}≈{{{16.9993}}} -> round it {{{x=17mph}}}