a) \(3,2.x+\left(-1,2\right).x+2,7=-4,9\)
\(\Leftrightarrow\left(3,2-1,2\right).x+2,7=-4,9\)
\(\Leftrightarrow2x=\left(-4,9\right)-2,7\)
\(\Leftrightarrow2x=-7,6\)
\(\Leftrightarrow x=\left(-7,6\right):2=-3,8\)
b) \(-5,6x+2,9x-3,86=-9,8\)
\(\Leftrightarrow\left(-5,6+2,9\right)x-3,86=-9,8\)
\(\Leftrightarrow\left(-2,7\right).x=-5,94\)
\(\Leftrightarrow x=\left(-5,94\right):\left(-2,7\right)=2,2\)