7 9
8--- - X = 5----
39 26
139 319
-X = -------- - ---------
26 39
6*139 - 4*319
-X= ------------------------
156
442
-X= - -------------
X = ---------------
130
X = 2-----
1)Пусть х=0,1111
sin4a*cos2a-cos4a*sin2a=sin(4a-2a)=sin2a.............................................