a) ( x - 15 ) - 75 = 0
x - 15 = 75
x = 75 + 15
x = 90
Vậy x = 90
b) 575 - ( 6x + 70 ) = 445
6x + 70 = 575 - 445
6x + 70 = 130
6x = 60
x = 10
Vậy x = 10
c) 315 + ( 125 - x ) = 435
125 - x = 120
x = 125 - 120
x = 5
Vậy x = 5
d) x - 105 : 21 = 15
x - 5 = 15
x = 20
Vậy x = 20
e) ( x - 105 ) : 21 = 1
x - 105 = 21
x = 21 + 105
x = 126
Vậy x = 126
a) (x-15)-75=0
x-15 = 0+75
x-15 = 75
x = 75 + 15
x = 90
b) 575-(6x+70)=445
6x+70 = 575-445
6x+70 = 130
6x = 130 - 70
6x = 60
x = 60:6
x = 10
d) x-105:21 = 15
x-105 = 15.21
x-105 = 315
x = 315 + 105
x = 420
e) (x-105):21 = 1
=> x-105 = 21
x = 105 + 21
x = 126
Tìm x:
a) ( x - 15 ) - 75 = 0 c) 315 + ( 125 - x ) = 435
x - 15 = 75 + 0 125 - x = 435 - 315
x - 15 = 75 125 - x = 120
x = 75 + 15 x = 125 - 120
x = 90 x = 5
b) 575 - ( 6x + 70 ) = 445 d) x - 105 : 21 = 15
6x + 70 = 575 - 445 x - 105 = 15 x 21
6x + 70 = 130 x - 105 = 315
6x = 130 - 70 x = 315 + 105
6x = 60 x = 420
x = 60 : 6
x = 10