The answer is the top one
You can determine if the answer is positive or negative because the even numbers are positive and the odd numbers are negative
The first one is 1.12867 because you need to set it up like this.
4=3.14(x)squared
4/3.14=x(squared)
x=1.12867
The second one is done simply by multiplying it out.
A=3.14(3x)squared
A=3.14(9x[squared])
A=28.26x[squared] -The squared is referring to the x.