`a) y^200=y`
`=> y^200 -y=0 `
`=>y(y^199-1)=0`
`=>` \(\left[ \begin{array}{l}y=0\\y^{199} -1=0\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}y=0\\y=1\end{array} \right.\)
`b) y^2008=y^2010`
`=> y^2008-y^2000=0`
`=> y^2008(1-y^2)=0`
`=>` \(\left[ \begin{array}{l}y^{2008}=0\\1-y^{2}=0\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}y=0\\y=1\\y=-1\end{array} \right.\)
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