187-149=38
589-399=190
78 005-69 906=8 099
49 087-8391=40 696
2 222 222 222-123 456 789=2 098 765 433
1 234 567 890-98 765 432=1 135 802 458
2x + 18 + 9x = 0
11x = -18
x = -18/11
x² + 9x + 18 = 0
D = 81 - 72 = 9
x₁ = (-9-3)/2 = -6
x₂ = (-9+3)/2 = -3
(64+52)÷2=58: 64+52=116 а 116 ÷2 = 58