<span>К+О+М+А+Н+Д+А=40 (7) </span>К+О+М+А+Н+Д+А/40=5.714285714285714*<span>Д+О+М(3)=17.14285714285714</span>
(2х - 9) : 5 = 3
(2х - 9) = 3* 5
2х - 9 = 15
2х = 15 + 9
2х = 24
х = 12
1,2* х^2 = 12.32
x^2 = 12.32 : 1.2
x^2 = 6.16 : 0.6
x^2 = 616 /100 : 6/10
x^2 = 616*10 / 100*6
x^2 = 616/60 = 154/5
x = +-корень из154/5