Answer:
x is 7·π/30
Step-by-step explanation:
The given equation is presented as follows;
tan(3·x/7 - π/5) = (-√3)/3
We have that arctan (√3)/3 = π/6, and tangent of an angle is negative in the second quadrant, we get;
arctan (-√3)/3 = -π/6 = 5·π/6
∴ tan(-π/6) = -√3/3 = tan(3·x/7 - π/5)
-π/6 = 3·x/7 - π/5
x = (-π/6 + π/5) × 7/3 = (6·π - 5·π)/30 × 7/3 = π/30 × 7/3 = 7·π/30
x = 7·π/30
