Question 1200577
UNKNOWN NUMBERS
r, speed if no wind
w, speed of the wind
KNOWN, GIVEN VALUES
d, distance either way about destination
{{{t[p]}}}, time flown with the wind
{{{t[m]}}}, time flown against the wind


{{{system(r+w=d/t[p],r-w=d/t[m])}}}


{{{r+w+r-w=d/t[p]+d/t[m]}}}


{{{2r=d(1/t[p]+1/t[m])}}}


{{{highlight_green(r=(d/2)((t[m]+t[p])/(t[p]t[m])))}}}

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{{{2w=d(1/t[p]-1/t[m])}}}


{{{highlight_green(w=(d/2)((t[m]-t[p])/(t[p]t[m])))}}}


Your example uses variables assigned
d=1920 miles
{{{t[p]=8}}} hours
{{{t[m]=12}}} hours