#1 There is no area of a cube. There is only a volume.
#2 The formula is

where s is the side.
Substitute 729 in V since that is the volume.

Take the cube root and you will get
9.
So the formula is
and the side is 9.
Step-by-step explanation:
1/6×100%=50/3%
3/24×100%=25/4%
3/8×100%=75/2%
=>50/3%+25/4%+75/2%+x=100%
=>100%-725/12%=x
=>x=59 and 5/12
-5x + 5y = 40 -20x +20y =160 -5x + 5(8) = 40
4x + 3y = 24 20x +15y =120 -5x + 40 = 40
35y = 280 -5x =0
y = 8 x = 0
Hope you understood this