Тема 1 » 6

Розв’яжіть рівняння: 1) –2/3х = 6; х = 6 : (–2/3); х = 6 • (–3/2); х = –9. 2) 4/7х = –16/21; х = –16/21 : 4/7; х = –16/21 • 7/4; х = –4/3 = –11/3. 3) (х - 1)/7 = 3; (х - 1)/7 = 21/7; х – 1 = 21; х = 21 + 1; х = 22. 4) х/2 + х/3 = 15; (3х + 2х)/6 = 90/6; 5х = 90; х = 18. 5) 4,7х – 2 = 4,5х + 3; 4,7х – 4,5х = 3 + 2; 0,2х = 5; х = 5 : 0,2; х = 25. 6) 2х – 3 – (3х – 2) = –8; 2х – 3 – 3х + 2 = –8; –х = –8 – 2 + 3; –х = –7; х = 7.