Answer:
The area increases from 81 yd² to 256 yd², which is an increase of 175 yd².
Explanation:
We need to find the area of the first square and the square after the expansion.
Area of square with side 9yd = 9 × 9
= 81 yd²
Area of square with side 9+7yd = (9+7) × (9+7)
= 16 × 16
= 256 yd²
Difference = 256 yd² - 81 yd²
= 175 yd²