Answer:
The width of the bookcase = 4ft
The height of the bookcase = 3ft
Step-by-step explanation:
Let H be the height of the bookcase
Let W be the width of the bookcase
W= 2H - 2ft
A bookcase of 4 shelves will have four widths and 2 heights
2H + 4W = 22ft
Put W= 2H - 2ft into the equation above
2H + 4(2H - 2ft) = 22ft
2H + 8H - 8ft = 22ft
10H - 8ft = 22ft
Collect like terms
10H = 22ft + 8ft
10H = 30ft
H = (30/10)ft
H= 3ft
The bookcase has a height of 3ft each
Put H= 3ft into the equation
2H + 4W = 22ft
2(3) + 4W= 22ft
6ft + 4W = 22fr
4W = 22ft - 6ft
4W = 16ft
W= (16/4)ft
W= 4ft
The width of the bookcase is 4ft each