№42. Реши примеры: 30−7; 37−4; 81+9; 58+30; 80−4; 90−3; 57−3; 29−8; 30−8; 38+40; 30+42; 40−7; 75−50; 84+6; 78−7; 92−10; 28+2; 60−6; 35+60; 45−30.

\(30-7=23\); \(37-4=33\); \(81+9=90\); \(58+30=88\); \(80-4=76\).

\(90-3=87\); \(57-3=54\); \(29-8=21\); \(30-8=22\); \(38+40=78\).

\(30+42=72\); \(40-7=33\); \(75-50=25\); \(84+6=90\); \(78-7=71\).

\(92-10=82\); \(28+2=30\); \(60-6=54\); \(35+60=95\); \(45-30=15\).