Ответ:При \(x=-2.1\): \(3.4\cdot(-2.1)+6=-7.14+6=-1.14\).При \(x=1.5\): \(3.4\cdot1.5+6=5.1+6=11.1\).При \(x=3.5\): \(3.4\cdot3.5+6=11.9+6=17.9\).При \(x=-2\): \(3.4\cdot(-2)+6=-6.8+6=-0.8\).При \(x=0.4\): \(3.4\cdot0.4+6=1.36+6=7.36\).