The length of a rectangle is twice its width and its perimeter is 42 cm. If the width of the rectangle is x cm, write an expression for the perimeter of the rectangle in terms of x.
Perimeter=
If the width is x, the length is twice this = 2x
And
Perimeter = 2 (W + L) so
Perimeter = 2 ( x + 2x)
Perimeter = 2 (3x)
Perimeter = 6x
42 = 2 ( x + 2x )
42 = 2 ( 3x)
42 = 6x
