Уравнение (1/4+1/5)x=1 4/5. (3 1/8+1 3/4)x=2 1/6. (2 1/12-1 5/6)x=3/4

(1/4 + 1/5) * x = 1 4/5; (5/20 + 4/20) * х = 9/5; 9/20 * х = 9/5; х = 9/5 : 9/20; х = 9/5 * 20/9; х = 20/5х = 4. Проверка:(1/4 + 1/5) * 4 = 1 4/5. (5/20 + 4/20) * 4 = 9/5; 9/20 * 4 = 9/5; 36/20 = 9/5; 9/5 = 9/5. Решение верно.

(3 1/8 + 1 3/4) * x = 2 1/6; (24/8 + 7/4) * х = 13/6; (24/8 + 14/8) * х = 13/6; 38/8 * х = 13/6; х = 13/6 : 38/8; х = 13/6 * 8/38; х = 104/228; х = 26/57. Проверка: (3 1/8 + 1 3/4) * 26/57 = 2 1/6; (24/8 + 7/4) * 26/57 = 13/6; (24/8 + 14/8) * 26/57 = 13/6; 38/8 * 26/57 = 13/6; 988/456 = 13/6; 13/6 = 13/6. Решение верно.

(2 1/12 - 1 5/6) * x = 3/4; (25/12 - 11/6) * х = 3/4; (25/12 - 22/12) * х = 3/4; 3/12 * х = 3/4; 1/4 * х = 3/4; х = 3/4 : 1/4; х = 3/4 * 4/1; х = 12/4; х = 3. Проверка: (2 1/12 - 1 5/6) * 3 = 3/4; (25/12 - 11/6) * 3 = 3/4; (25/12 - 22/12) * 3 = 3/4; 3/12 * 3 = 3/4; 1/4 * 3 = 3/4; 3/4 = 3/4. Решение верно.