5/9x+2/3x-1/2x=7/12 посчитайте

:5/9Х+2/3Х-1/2Х=7/12

20/36Х+24/36Х-18/36Х=21/36

26/36Х=21/36

Х=21/36:26/36

Х=21/26

Проверка

5/9•21/26+2/3•21/26-1/2•21/26=7/12

(5/9+2/3-1/2)•21/26=7/12

13/18•21/26=7/12

7/12=7/12