Реши уравнение2) 300 - х *5 = 2104) (300 - х)

2) 300 - х*5 = 210;
- х*5 = 210 - 300;
- х*5 = - 90;
х = -90/(-5).
х = 18.
4) (300 - х)*5 = 210.
(300 - х)*5/5 = 210/5;
300 - х = 42;
- х = 42 - 300;
х = -258/(-1);
х = 258.
5) (300 - 18)*х = 1410;
282*х = 1410;
х = 1410/282;
х = 5.
6) (150 - 20):х = 65;
130:х = 65.
х = 130/65;
х = 2.
7) 5*х - 600 = 900;
5*х = 900 + 600;
5*х = 1500;
х = 1500/5;
х = 300.
8) (х + 4)*7 = 350;
(х + 4)*7/7 = 350/7;
х + 4 = 50;
х = 50 - 4;
х = 46.