5=50-2x^2
-45 = -2x^2
22.5 = x^2
x = sqrt(22.5)= +-4.743
I would change #4 to 'keyboarding' , but I hate making suggestions.
Area of a circle is pi x r^2
3.14 x (5^2) = 3.14 X 25 = 78.5 SQUARE CENTIMETERS also written as 78.5 cm^2
Nothing I know of....but it will be in the dimension of 'units'^3
Maybe THIS is for what you are looking?
d= diameter = 2r and r = 1/2 d
(1/2d)^2 x d = 1/4 d^2 x d = 1/4 d^3
or r^2 x 2r = 2 r^3
10/3 x 5 = 50/3 = 16 2/3
m^3 x m^6 = m^(3+6) = m^9
\(\sqrt[3]{16}\)= \(\sqrt[3]{8 x 2}\)= 2 \(\sqrt[3]{2}\)
BUT....they are all young boys.
