Question 1035360
Let n equal his speed before lunch. Then:
300/n+105/n-15=9
300(n-15)+105n=9(n)(n-15)
300n+105n-4500=9n^2-135n
9n^2-540n+4500=0
n^2-60n+500=0
(n-50)(n-10)=0
n=50 or 10
The only reasonable answer is his speed before lunch was 50 mph, 35 mph after lunch!!!!!!!!!