Question 169350
let x="speed on 2nd part", so x+5="speed on 1st part" __ t=d/r


90/(x+5) + 16/x = 5 __ multiplying by x(x+5) __ 90x+16x+80=5x^2+25x


5x^2-81x-80=0 __ use quadratic formula to find x




ANSWER BELOW




x=17.13 (approx)