Cześć ;-)
Obliczenia
[tex]5\cdot36=5\cdot(30+6)=5\cdot30+5\cdot6=150+30=\boxed{180}\\\\21\cdot4=(20+1)\cdot4=20\cdot4+1\cdot4=80+4=\boxed{84}\\\\8\cdot55=8\cdot(50+5)=8\cdot50+8\cdot5=400+40=\boxed{440}\\\\38\cdot5=(30+8)\cdot5=30\cdot5+8\cdot5=150+40=\boxed{190}[/tex]
Pozdrawiam!