Question

Помагите пожалуйста !!!20балов дам
[6]

Answer 1

2х - 276 = 133
2х = 133 + 276
2х = 409
х = 409/2
х = 204.5

287 + (120 - х) = 300
120 - х = 300 - 287
120 - х = 13
х = 107

300 - 78/х = 287
78/х = 300 - 287
78/х = 13
13х = 78
х = 78/13
х = 6

750 + 10х = 750
10х = 750 - 750
10х = 0
х = 0