Answer:
x = a/7
Explanation:
Area is length x width, so let's call our unknown, the length, x
So the total area is 7 (the width) times x
If the total area is a, then we can write the equation a = 7(x)
Next, we have to isolate the variable for the length, x
To do this, we divide both sides by 7, leaving a/7 = x, or x = a/7