Answer:
1) Distance=Speed*time
90=(x+1)*(x)+(2x+5)(x-1)
90=x^2+x+2x^2-2x+5x-5
3x^2+4x-95=0
2) 3x^2+4x-95=0. Using quadratic formula, we get
x=(-4±sqrt(16-4*3*(-95)))/6, x=5 or - 19/5 but since x also represents time, it can't be negative.
3) Total time take she took for the journey is x+x-1=2x-1=2*5-1=9 hours
