(log 3 (x-2)-sin(pix/2))^2+(x-5)^2=0 --->подробно
(log3(x-2)- 1)^2+(x-5)^2=0
(log3(x-2)-log3(3))^2+(x-5)^2=0
(x-5)^2+(x-5)^2=0
x^2-10x+25=0
D=100-100=0
x=10/2
x=5
S={5}