Řeš v ℝ nerovnice:
\large 12-3,1 x \geq 2\left( 0,9+x\right)
\large K = \left( - \infty ;3\right \rangle
\large K = \left( - \infty ;1\right \rangle
\large K = \left( - \infty ;2\right \rangle
\large K = \left( - \infty ;0\right \rangle