$$ z = 2a + 3y $$

$$ M(s)<M(t)<|M| = m $$

$$ y'' = c\{f[y',y(x)] + g(x)\} $$

$$ x^2 \ a_n \ x^n_i $$

$$ \sum_{i=1}^n \int_a^b $$

$$ A = \begin{bmatrix} a_{11} & a_{12} & \cdots & a_{1n}\\ a_{21} & a_{22} & \cdots & a_{2n}\\ \vdots & \vdots & \ddots & \vdots \\ a_{m1} & a_{m2} & \cdots & a_{mn} \end{bmatrix} $$

$$ \begin{pmatrix} a_{11} & a_{12} \\ a_{21} & a_{22} \end{pmatrix} \begin{pmatrix} b_{11} & b_{12} & b_{13}\\ b_{21} & b_{22} & b_{23} \end{pmatrix} = \begin{pmatrix} a_{11}b_{11}+ a_{12}b_{21} & a_{11}b_{12}+ a_{12}b_{22} & a_{11}b_{13}+ a_{12}b_{23}\\ a_{21}b_{11}+ a_{22}b_{21} & a_{21}b_{12}+ a_{22}b_{22} & a_{21}b_{13}+ a_{22}b_{23} \end{pmatrix} $$