Answer:
10
Step-by-step explanation:
4+5=9 and 1/2+1/2 =1 so 9+1=10
Follow PEMDAS.
Parenthesis
Exponents
Multiplication & Division
Addition & Subtraction
Alright, do multiplication first, then division. Then, do subtraction then addition.

Hope this helped!
Answer:
482.8 cm
Step-by-step explanation:
A=2(1+sqrt2)a^2=2·(1+squrt2)·10^2=482.84271