A slug travels 4miles at Xmph then another 3 miles at X+4mph

write an expression to show this situation---

i think its 4/x + 3/x+4

correct me if wrong,,, then hard bit....

the total time taken is 5 hours , form an equation in x, of the type px²+qx+r=0

it give me space to answer as below....

_____________=0

wot answer??? quick