√((√(16-6*√7)+√7)*3)=√((√(9-2*3*√7+7)+√7)*3)=√((√(3-√7)^2+√7)*3)=
X^2 + (x+14)^2= 26^2
x^2 + x^2 +28x+196-676=0
2 x^2 +28x-480=0
X²<span>-7x+c=0
</span>х₁+х₂=7 х₁+х₂=7
х₁²-х₂²=21 ⇔ х₁-х₂=3 ⇒
х₁=5 х₂= 2
с=2*5=10
5x-2x-1=13
3x=14
x=14/3
x=4⅔
-4cos(a+270)-2,4(540-a)-0,6(a+360)=
-4cos a-1080cos-1296-2,4a-0,6a-216=
-4cos a-1080cos-3a-1512=
-4cos(a+240)-3(a-54)=0
-4cos=0,a1=-240,a2=54
cos=0