Question 1059997
.
An airplane flies  355 miles to city A. Then, with better winds, it continues on to city B,  448 miles from A, 
at a speed  15.8 mi/h greater than on the first leg of the trip. The total flying time was 5.20 h . 
Find the speed at which the plane traveled to city A.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


<pre>
Your equation is

{{{355/u + 448/(u+15.5)}}} = 5.2.

First addend on the left side is the flying time to get A.
The second addend on the left side is the flying time From A to B.

Solve the equation to get the unknown u, the speed under the question.

As a first step, multiply both sides of the equation by 8*u*(u+15.5).

Then simplify and solve the quadratic equation.
</pre>