As per the problem
A jet flew for 2 hrs before strong head winds reduced its speed by 40 mph.
It took the plane 5 hrs to travel 1,380 miles
Total time=5 hrs, Time of fly before headwinds[tex] =2 [/tex],
Time of fly in headwinds[tex] =5-2=3 hrs [/tex]
Let the speed before head winds [tex] =v\\ [/tex]
Then speed in headwinds[tex] =(v-40)\\ [/tex]
As we know that
[tex] \text{Distance =Speed*Time}\\
\\
[/tex]
Hence using this formula and the given data we can write
[tex] 1380=2v+3(v-40)\\
\\
\text{Simplify we get}\\
\\
3v-120+2v=1380\\
\\
5v=1380+120\\
\\
5v=1500\\
\\
v=300mph\\ [/tex]
Hence speed before flying into the headwinds=300mph
