Let the width be x.
Then,length = 2x + 3
Area of rectangle = 560 [ Given ]
⇒ l × b = 560
⇒ ( 2x + 3 ) x = 560
⇒ 2x² + 3x - 560 = 0
⇒ 2x² + 35x - 32x - 560 = 0
⇒ x ( 2x + 35 ) - 16 ( 2x + 35 ) = 0
⇒ ( x - 16 ) = 0 and ( 2x + 35 ) = 0
⇒ x = 16 and x = -35/2 [ Ignore negative number ]
★ Width = x = 16 cm
★ Length = 2x + 3 = 2 × 16 + 3 = 32 + 3 = 35 cm