А) 5,04 : (104,2-х)=1,2
5,04: (104,2 - х) = 1,2 , х≠104,2
![\frac{126}{25} : (\frac{521}{5} -x) =1,2 \frac{126}{25} : (\frac{521}{5} -x) =1,2](https://tex.z-dn.net/?f=%5Cfrac%7B126%7D%7B25%7D%20%3A%20%28%5Cfrac%7B521%7D%7B5%7D%20-x%29%20%3D1%2C2)
![\frac{126}{25} : \frac{521-5x}{5} =1,2 \frac{126}{25} : \frac{521-5x}{5} =1,2](https://tex.z-dn.net/?f=%5Cfrac%7B126%7D%7B25%7D%20%3A%20%5Cfrac%7B521-5x%7D%7B5%7D%20%3D1%2C2)
![\frac{126}{25} *\frac{5}{521-5x} \frac{126}{25} *\frac{5}{521-5x}](https://tex.z-dn.net/?f=%5Cfrac%7B126%7D%7B25%7D%20%2A%5Cfrac%7B5%7D%7B521-5x%7D)
![\frac{126}{5} * \frac{1}{521-5x} = 1,2 \frac{126}{5} * \frac{1}{521-5x} = 1,2](https://tex.z-dn.net/?f=%5Cfrac%7B126%7D%7B5%7D%20%2A%20%5Cfrac%7B1%7D%7B521-5x%7D%20%3D%201%2C2)
![\frac{126}{5 (521 - 5x)} =1,2 \frac{126}{5 (521 - 5x)} =1,2](https://tex.z-dn.net/?f=%5Cfrac%7B126%7D%7B5%20%28521%20-%205x%29%7D%20%3D1%2C2)
126 = 6 (521-5х)
21 = 521 - 5х
5х= 521-21
5х = 500
х=100, х ≠ 104,2
х = 100
Б) 1,2 + 4,5 - 0,7 = 1,01
5,7х - 0,7 = 1,01
5,7х = 1,01 + 0,7
5,7 х = 1,71
х = 0,3
А) 6,72: (203,2-х) = 2,1 , х≠203,2
![\frac{168}{25} : (\frac{1016}{5} - x) = 2,1 \frac{168}{25} : (\frac{1016}{5} - x) = 2,1](https://tex.z-dn.net/?f=%5Cfrac%7B168%7D%7B25%7D%20%3A%20%28%5Cfrac%7B1016%7D%7B5%7D%20-%20x%29%20%3D%202%2C1)
![\frac{168}{25} : \frac{1016-5x}{5} = 2,1 \frac{168}{25} : \frac{1016-5x}{5} = 2,1](https://tex.z-dn.net/?f=%5Cfrac%7B168%7D%7B25%7D%20%3A%20%5Cfrac%7B1016-5x%7D%7B5%7D%20%3D%202%2C1)
![\frac{168}{25} * \frac{5}{1016-5x} = 2,1 \frac{168}{25} * \frac{5}{1016-5x} = 2,1](https://tex.z-dn.net/?f=%5Cfrac%7B168%7D%7B25%7D%20%2A%20%5Cfrac%7B5%7D%7B1016-5x%7D%20%3D%202%2C1)
![\frac{168}{5} * \frac{1}{1016 - 5x} = 2,1 \frac{168}{5} * \frac{1}{1016 - 5x} = 2,1](https://tex.z-dn.net/?f=%5Cfrac%7B168%7D%7B5%7D%20%2A%20%5Cfrac%7B1%7D%7B1016%20-%205x%7D%20%3D%202%2C1)
![\frac{168}{5(1016-5x)} = 2,1 \frac{168}{5(1016-5x)} = 2,1](https://tex.z-dn.net/?f=%5Cfrac%7B168%7D%7B5%281016-5x%29%7D%20%3D%202%2C1)
168 = 10,5 (1016 - 5х)
168 = 10668 - 52,5 х
52,5х = 10668 - 168
52,5х = 10500
х = 200, х≠203,2
х = 200
Б) 1,3х+3,8х - 0,03 = 2, 01
5,1х - 0,03 = 2,01
5,1 = 2,01+0,03
5,1х=2,04
х=0,4