Question

cos(-п/3)-cos(2п/3)+4
-3/7x=3целых6/7

Answer 1

cos(-π/3)-cos(2π/3)+4=1/2-(-1/2) +4=1/2+1/2+4=1+4=5

-3/7*x=3 6/7
x=3 6/7:(-3/7)=-27/7*7/3=-9