7-[100x52:13-5x(3x120-2xX)]=20x2
7-[100x52:13-5x(3x120-2xX)]=40
[100x52:13-5x(3x120-2xX)]=40+7
[100x52:13-5x(3x120-2xX)]=47
[52:13-5x(3x120-2xX)]=100x47
[52:13-5x(3x120-2xX)]=4700
[13-5x(3x120-2xX)]=4700x52
[13-5x(3x120-2xX)]=244.400
[5x(3x120-2xX)]=244.400-13
[5x(3x120-2xX)]=244.387
(3x120-2xX)=244.387x5
(3x120-2xX)=1.221.935
(120-2xX)=1.221.935x3
(120-2xX)=3.665.805
2xX=3.665.805-120
2xX=3.665.685
X=3.665.685x2
X=7.331.370