The perimeter of a rectangle = 2(l + w)
l = length
w = width
In this problem,
w = x
l = x + 30
the perimeter = 148
Let's plug our values into the perimeter formula above.
148ft = 2(x + x + 30ft)
Combine like terms.
148ft = 2(2x + 30ft)
Distribute the 2
148ft = 4x + 60
Subtract 60 from both sides
88ft = 4x
Divide both sides by 4
22ft = x
The width = x = 22ft
The length = x + 30 = 22 + 30 = 52ft
4x -2y = 60
4x -3y = 26
(-) (+) (-)
__________
1y = 34
y = 34
To find x
4x -2y = 60
4x -(2)(34) = 60
4x -68 = 60
4x = 60 + 68
4x = 128
x = 32
Answer:
x=32 ; y=34
after 4 days 88 boats will have passes under the bridge
