`1)`
`2019^2020 + 2019^2019 - 2020xx2019^2019`
`= 2019^2019 ( 2019 + 1 ) - 2020xx2019^2019`
`= 2020xx2019^2019 - 2020xx2019^2019`
`= 0 `
`2)`
`3^x-2019 xx 3^2019=27`
`3^x-2019xx3^2019 = 3^3`
`3^x-2019 xx 3^2019 - 3^3 = 0`
`3^3 ( 3^x-2019xx3^2016 - 1 ) = 0`
`3^x-2019xx3^2016 - 1 = 0`
`3^x-2019xx 3^2016 = 1`
`3^x-2019 = 1 / 3^2016`