Explanation:
8) earning of 4.5 hours=$54
earning of 1 hour=$54/4.5
earning of 1 hour=$12
9)perimeter=36 feet
length is twice so
length=2x
width=x
perimeter = 2(length+width)
36=2(2x+x)
2x+x=36/2
3x=18
x=6
width=6 feet
length=2(6)
length=12 feet
Area of rectangle= length * width
area=12*6 sq.feet
area= 72 sq.feet