Роздiл 5. Лiнiйнi рiвняння та ix системи » 764

Розв’яжіть рівняння: 1) 12 – 4x = 40; –4x = 40 – 12; –4x = 28; x = –7. 3) 15 – 3y = 14 – 2y; –3y + 2y = 14 – 15; –y = –1; y = 1. 5) 35 + 17y – 5 = 2y; 17y – 2y = –35 + 5; 15y = –30; y = –2. 2) 7y – 27 = –2y; 7y + 2y = 27; 9y = 27; y = 3. 4) 26 + 2x = 7x – 9; 2x – 7x = –9 – 26; –5x = –35; x = 7. 6) 12z = 5z – 18 – 2z; 12z – 5z + 2z = –18; 9z = –18; z = –2.