Question 271148
After 30 miles time is 30/x
Next part is 20/(x + 15)
So 30/x + 20/(x + 15) = 1
LCM is x(x+15
so 30(x + 15) + 20x = x(x+15)
30x + 450 + 20x = x^2 + 15x
x^2 - 35x - 450 = 0
(x - 45)(X + 10) = 0
x = 45 or -10
initial speed is 45 mph