Question 255743
x=y+1
xy/(x+y)=1.2
Substitute (y+1) for x & solve for y
(y+1)y/(y+1+y)=1.2
(y^2+y)/(2y+1)=1.2 cross multiply.
y^2+y=1.2(2y+1)
y^2+y=2.4y+1.2
y^2+y-2.4y-1.2=0
y^2-1.4y-1.2=0
(y-2)(y+.6)=0
y-2=0
y=2 hours for Henry.
x=2+1=3 hours for George.
Proof:
2*3/(2+3)=1.2
6/5=1.2
1.2=1.2