Вправи 401 - 500 » 426

Розв’яжіть рівняння: 1) 31/3 – 11/20х = 114/15; 11/20х = 31/3 – 114/15; 21/20х = 12/5; х = 7/5 : 21/20; х = 7/5 ∙ 20/21; х = 11/3. 2) 3/8х + 7/12х – 5/6х = 9/32; (3/8 + 7/12 – 5/6) х = 9/32; 1/8х = 9/32; х = 9/32 : 1/8; х = 9/32 ∙ 8; х = 21/4. 3) 21/3 : х – 11/6 = 15/9; 7/3 : х = 15/9 + 11/6; 7/3 : х = 213/18; х = 7/3 : 49/18; х = 7/3 ∙ 18/49; х = 6/7. 4) 21/3 : (х – 11/6) = 15/9; х – 11/6 = 21/3 : 15/9; х – 11/6 = 7/3 ∙ 9/14; х – 11/6 = 11/2; х = 11/2 + 11/6; х = 22/3.