Let w be the width of the rectangle. We can write an addition equation to represent the relationship between the width and length of the rectangle, as follows: w + 4 = 7
To find the width of the rectangle, we can solve this equation by adding 4 to both sides of the equation, which gives us: w + 4 + 4 = 7 + 4
w = 11
Therefore, the width of the rectangle is 11 inches.