`17, (x + 1)^96 = (x + 1)^6`
`⇒` \(\left[ \begin{array}{l}x + 1=0\\x+1=1\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}x = -1\\x=0\end{array} \right.\)
`18, 5x = 4x^3`
`⇒ 5x - 4x^3 = 0`
`⇒ x(5 - 4x^2) = 0`
`⇒` \(\left[ \begin{array}{l}x=0\\5 - 4x^2=0\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}x=0\\ 4x^2=5\end{array} \right.\)
`⇒ x = 0` hoặc `x^2 = 5/4`
`⇒ x = 0` hoặc `x = \frac{\sqrt{5}}{2}`
`19, 9^(x - 1) = 9`
`⇒ x - 1 = 1`
`⇒ x = 2`
`20, 2021^x = 1`
`⇒ x = 0`
`21, 2^x : 32 = 2`
`⇒ 2^x = 64`
`⇒ x = 6`
`22, 5^(x + 3) = 625`
`⇒ 5^(x + 3) = 5^4`
`⇒ x + 3 = 4`
`⇒ x = 1`
`23, (2x + 5)^6 = (2x + 5)^9`
`⇒` \(\left[ \begin{array}{l}2x + 5=0\\2x + 5=1\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}2x = -5\\2x=-4\end{array} \right.\)
`⇒ x = (-5)/2` hoặc `x = -4`
