`(7x-11)^3=100-73`
`⇒(7x-11)^3=27`
`⇒(7x-11)^3=3^3`
`⇒7x-11=3`
`⇒7x=3+11`
`⇒7x=14`
`⇒x=14:7`
`⇒x=2`
$5^{x+1}$ `+` $5^{x+2}$ `=750`
`⇒5^x.5^1+5^x.5^2=750`
`⇒5^x(5+5^2)=750`
`⇒5^x.30=750`
`⇒5^x=750:30`
`⇒5^x=25`
`⇒5^x=5^2`
`⇒x=2`
$(2x-1)^{2018}$ `=` $(2x-1)^{2019}$
`⇒` $(2x-1)^{2018}$ `-` $(2x-1)^{2019}$ `=0`
`⇒` $(2x-1)^{2018}$ . `[(2x-1)-1]` `=0`
`⇒` \(\left[ \begin{array}{l}(2x-1)^{2018}=0\\2x-1-1=0\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}2x-1=0\\2x-2=0\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}2x=1\\2x=2\end{array} \right.\)
`⇒` \(\left[ \begin{array}{l}x= \frac{1}{2}\\x=1\end{array} \right.\)
