Question

Write an inequality for x that would give a rectangle with the length of 3ft and width of x+5ft , a
`perimeter` of at least 300 ft.

Answer 1

P≥300
300≤P
P=2(L+W)
300≤2(L+W)

L=3
W=x+5

300≤2(3+x+5)
300≤2(8+x)
divide both sides by 2
150≤8+x
minus 8 both sides
142≤x

x is at least 142
width is at least 147