22.1. Calculate the expression $2 x^{4}+3 x^{2} y^{2}+y^{4}+y^{2}$, given that $x^{2}+y^{2}=1$.

$$
\text { (7-8 grades) }
$$
22.1. Taking into account that $x^{2}+y^{2}=1$, we get:

$$
\begin{gathered}
2 x^{4}+3 x^{2} y^{2}+y^{4}+y^{2}=2 x^{4}+2 x^{2} y^{2}+x^{2} y^{2}+y^{4}+y^{2}= \\
=2 x^{2}\left(x^{2}+y^{2}\right)+y^{2}\left(x^{2}+y^{2}\right)+y^{2}=2 x^{2}+y^{2}+y^{2}= \\
=2\left(x^{2}+y^{2}\right)=2
\end{gathered}
$$