\(\left(x-5\right)-\left(2x+7\right)=-8\\ x-5-2x-7+8=0\\ -x=4\\ x=-4\)
1, x - 45 = 48 - 68
x - 45 = - 20
x = (- 20) + 45
x = 25
Vậy x = 25
2, 35 + 5. (6 - x) = ( - 12) - ( - 112)
35 + 5. (6 - x) = 100
40. (6 - x) = 100
6 - x = 100 : 40
6 - x = 25
x = 6 - 25
x = - 19
Vậy x = - 19
3, 157 - (x - 124) = - 483
x - 124 = 157 - (- 483)
x - 124 = 640
x = 640 + 124
x = 764
Vậy x = 764