(в+3а+а-4в)÷(18а*18а*в*21ав*21ав)=(4а+(-4в))÷(324ав*441ав)
2Y9*3 + 4Y16*3 - 1/5 Y25*3 - 9Y3 =
=2*3Y3 + 4*4Y3 - 0,2*5Y3 -9Y3 =
=6Y3 +16Y3 - Y3 -9Y3 = 12Y3
2.(51,8+44,3+48,2-24,3)*1/3=(100+20)*1/3=40
4.-11,401-23,17+4,401-10,83=-11,401-23,17+4,401-10,83=-11,401+4,401-(23,17+10,83)=-7-34=-41