5 sin(/3+x)+7 sin(/3-x)=0

5sin(pi/3 + x) + 7sin(pi/3 - x) = 0
5sin(pi/3)*cos(x) + 5cos(pi/3)*sin(x) + 7sin(pi/3)*cos(x) - 7cos(pi/3)*sin(x) = 0
12sin(pi/3)*cos x - 2cos(pi/3)*sin x = 0
12*3/2*cos x - 2*1/2*sin x = 0
63*cos x - sin x = 0
sin x = 63*cos x
tg x = 63
x = arctg(63) + pi*k