Days in boston=x
days in colorado=1.4x
boston+colorado=2.4x
475=2.4x
475/2.4=2.4x/2.4
198=x
198*1.4=277
days in boston=198
days in colorado=277
198+277=475
154.35 - 10.37 = 143.98
143.98 - 27.83 = 116.15
10.37 = 116.15x
x = 0.0893
Change x to percent form to get 8.93% tax rate.
I)
The Midpoint M of the line segment AB is found using the Midpoint formula:

ii)
the slope of the line through A and B is found by the slope formula:

iii)
the product of the slopes of 2 perpendicular lines is -1, so the slope of the line perpendicular to the line through A and B is -1/(-1)=1
iv)
the equation of the line with slope 1, which contains point M(3, 9) is found by the slope point form equation of a line:
y-9=1(x-3)
y-9=x-3
y=x+6
Answer: y=x+6
360=x+x+(2x+3)+(2x+3)
we have 360=2x+2x+2x+6
360-6=6x
354=6x
x=354/6=59
x=59