P = 2((10 + x) + x)
The perimeter of a rectangle is the sum of the length and width multiplied by 2
P = 2(l + w)
[to simplify the expression]
P = 2 × (l + w)
[using x to represent the width]
w = x
l = x + 10
P = 2 × ((10 + x) + x)
P = 2((10 + x) + x)
