`tan (5 - x) = 2020`
`<=> 5 - x = arctan 2020 + kπ`
`<=> x = -5 - arctan 2020 + kπ` `(k ∈ ZZ)`
`sin (7x + π/3) = -(\sqrt{3})/2`
`<=> sin (7x + π/3) = sin (-π/3)`
`<=>` \(\left[ \begin{array}{l}7x + \dfrac{π}{3} = -\dfrac{π}{3} + k2π\\7x + \dfrac{π}{3} = \dfrac{4π}{3} + k2π\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}x = -\dfrac{2π}{21} + k\dfrac{2π}{7}\\x = \dfrac{π}{7} + k\dfrac{2π}{7}\end{array} \right.\) `(k ∈ ZZ)`
`cot (5x + π/6) = ±sqrt{3}`
`<=> 5x + π/6 = ±(π)/6 + kπ`
`<=>` \(\left[ \begin{array}{l}5x = kπ\\5x = -\dfrac{π}{3} + kπ\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}x = k\dfrac{π}{5}\\x = -\dfrac{π}{15} + k\dfrac{π}{5}\end{array} \right.\) `(k ∈ ZZ)`
