\(0,69\cdot12,34+12,34\cdot0,41-1,234\)
\(=12,34\cdot\left(0,69+0,41\right)-1,234\)
\(=12,34\cdot1,1-1,234\)
\(=13,574-1,234\)
\(=12,34\)
\(0,69\cdot12,34+12,34\cdot0,41-1,234\)
\(=0,69\cdot12,34+12,34\cdot0,41-12,34\cdot0,1\)
\(=12,34\cdot\left(0,69+0,41-0,1\right)\)
\(=12,34\cdot1=12,34\)