Answer:
X^2 + 2(30x) + 900
Step-by-step explanation:
You multiply the sides of each square and add them to get the total of the whole square. For the top left square, you multiply x and x. For the top right, you multiply 30 and x. For the bottom left, you multiply 30 and x as well. And for the bottom right, you multiple 30 and 300. Add these together and you get X^2 + 2(30x) + 900.
