Draw a diagram.
Find the total area of the outside rectangle by adding
the area of the inside rectangle to the area of the walkway.
30 + 10 = 40 sq m
If x meters of walkway was added to each side, write an
expression for each side of the outside rectangle.
length = 5 + 2x
width = 2 + 2x
Now write an equation of the form (length)(width) = area and solve for x.
Make sure you remember to answer the original question.