Question 904931
let's distance be {{{d}}}, time {{{t}}}, and speed {{{s}}}

if you leave you house at {{{t[1]=5:20}}} a.m. to get to work, which is {{{d=20 miles}}} away; if you drive {{{s=40mph}}},what time {{{t[2]}}}, will you arrive at work 
{{{t=t[2]-t[1] }}} 


so, {{{d=s*t}}} 

 {{{d=s*(t[2]-t[1])}}} 

given:
{{{d=20mil}}} 
{{{s=40(mil/h)}}}
{{{t[1]=5:20=5h+20/60h=5h+0.33h=5.33h}}} a.m.

{{{d=s*(t[2]-t[1])}}} ...plug in given values

{{{20mil=40(mil/h)*(t[2]-5.33h)}}} ...solve for {{{t[2]}}} 

{{{20cross(mil)/40(cross(mil)/h)=(t[2]-5.33h)}}}

{{{0.5h=t[2]-5.33h}}}

{{{0.5h+5.33h=t[2]}}}

{{{5.83h=t[2]}}}............... time that will you arrive at work


so, {{{t=t[2]-t[1] }}} 

{{{t=5.83h -5.33h }}}
 
{{{t=0.5h}}} or {{{t=30min}}}... time you will spend driving to work