Question

The length of a rectangle is 6 m more than twice the width. if the area of the rectangle is 140m^2, find the dimensions

Answer 1

Length(l)= 2w+6
Width(w)= w
Area(A)= 140 m²
Area= l*w
140 = l*w
140= (2w+6)w
140= 2w²+6w( divide each side by 2)
70= w²+3w
w²+3w -70= 0
(^^^^^^Factor out expression)
(w-7)(w+10)= 0 (set each expression equal to zero and use the positive answer as the value for "w"(because a negative width is impossible))

w-7=0
w=7m

w+10=0
w= -10m (Impossible for a physical measurement to negative: therefore This "w" value is incorrect)

Use w=7 to find "l"
l= 2w+6
l=2(7)+6
l=14+6
l=20 m

Answer:
The dimensions of a rectangle are length and by width. For this rectangle the dimensions are 20 meters by 7 meters.
(width= 7 meters)
(length= 20 meters)