7,2х= 2 - 2,3( 4-2х)
7,2х = 2 - 2,3 *4 - 2,3 * (-2х)
7,2х = 2- 9,2 + 4,6х
7,2х - 4,6х = -7,2
2,6х = -7,2
х=-7,2 : 2,6 = - 72/26 =- 36/13
х= - 2 10/13
проверим:
7,2 * (-2 10/13) = 2 - 2,3 (4 - 2 * (-2 10/13))
72/10 * (-36/13) = 2- 2,3 ( 4 + 5 7/13)
- 1296/ 65 = 2 - 23/10 * 124/13
- 19 61/65 = 130/65 - 1426/65
- 19 61/65 = -1296/65
- 19 61/65 = - 19 61/65