Розділ 1. ЦІЛІ ВИРАЗИ » 279

Розв’яжи рівняння. a) (4x – 5) – (7x + 8) = 2; 4x – 5 – 7x – 8 = 2; –3x = 5 + 8 + 2; –3x = 15|: (–3); x = –5. б) 9z + 17 – (4z – 6) = 38; 9z + 17 – 4z + 6 = 38; 5z = –17 – 6 + 38; 5z = 15|: 5; z = 3. в) (5x + x3 – 7) – (2x3 + 3x) = –(1 + x3); 5x + x3 – 7 – 2x3 – 3x = –1 – x3; –x3 + 2x= –x3 + 7 – 1; 2x = 6|: 2; x = 3. г) 19 – (3x2 – 2x) – (6x – x2) = 7 – 2x2; 19 – 3x2 + 2x – 6x + x2 = 7 – 2x2; –2x2 – 4x = –2x2 – 19 + 7; –4x = –12|: (–4); x = 3.