The answer is 3/22
I see the answer 17/125 around a lot, and that's not wrong but I don't think it's simplified enough
5000-4000=1000
Difference means subtraction.
7 squared equals 7 times 7
Answer 243mm^2
Explanation:
I first split the shape into two smaller shapes. Then I found those two areas and added them! (18x12)+(9x3)=243