For the state of plane stress shown in the figure, the minimum principal stress is $-7 \mathrm{MN} / \mathrm{m}^{2}$. The normal stress $\sigma_{x}$ in $M N / m^{2}$ is equal to__________________ $\quad$ (round to nearest integer).
For the state of plane stress shown in the figure, the minimum principal stress is $-7 \mathrm{MN} / \mathrm{m}^{2}$. The normal stress $\sigma_{x}$ in $M N / m^{2}$ is equal to__________________ $\quad$ (round to nearest integer).