WolframAlpha computational knowledge AI
solve{-1.1x1+3.8x2+7.2x3-2.1x4=3.5, 0.1x1+0.2x2+5.4x4=2.9, 7.6x1+2.8x2-1.4x3+3.2x4=11.1, (x2,x3,x4)}