3 The length of a mobile phone is twice the width.
There is a border around the screen.
The border is 1.5cm wide at the top and bottom.
The border is 0.25 cm wide at the sides.
The perimeter of the screen is 32 cm.
Let the width of the phone be.xcm.
(a) Form an equation in x.
(b) Hence find the area of the screen in cm².