According to the problem, the length is 2 centimetres longer than the width, so the length can be expressed as:
l = w + 2
length = width + 2
The perimeter of a rectangle is twice the sum of its length and width, so we can set up an equation to represent the perimeter given in the problem:
P = 2(l + w)
Substituting the expression for l in terms of w, we get:
P = 2((w + 2) + w)
Simplifying this expression, we get:
P = 2(2w + 2)
P = 4w + 4
We know that the perimeter of the rectangle is 86 centimetres, so we can substitute this value into the equation:
86 = 4w + 4
Subtracting 4 from both sides:
82 = 4w
Dividing both sides by 4:
w = 20.5
Therefore, the width of the rectangle is 20.5 centimetres.
The equation that could be used to find the width of the rectangle is:
4w + 4 = 86
where w represents the width of the rectangle in centimetres.