Ответ:
а) 2х = 4/7
х = 4/7 * 1/2
х = 2/7
б) -10z = 2/5
z = -2/5 *1/10
z = - 1/5 * 1/5
z = - 1/25
в) 3х = -1/3
х = - 1/3 * 1/3
х = -1/9
-16,54+(-9,31)-11,27-(-23,38)=
=-16,54-9,31-11,27+23,38=-13,74