(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}

3x(x+y+c)-3y(x-y-c)-3c(x+y-c)=3x^2+3xy+3xc-3xy+3y^2+3yc-3cx+3cy+3c^2=

=3x^2+3y^2+3c^2