(x-10) . 11 = 22
x - 10 = 22 : 11
x - 10 = 2
=> x = 12
b, 2x + 15 = (-27)
2x = (-27)- 15
2x = - 42
=> x = -21
c , tự làm
a) ( x - 10 ) . 11 = 22
x - 10 = 22 : 11
x - 10 = 2
x = 2 + 10
x = 12
Vậy x = 12
b) 2x + 15 = - 27
2x = - 27 - 15
2x = - 42
x = - 42 : 2
x = - 21
Vậy x=-21
c) - 765 - ( 305 + x ) = 100
305 + x = - 765 - 100
305 + x = - 865
x = - 865 - 305
x = - 1170
Vậy x=-1170
d)2x:4=16
2x:22=24
2x-2=24
=> x-2=4
x=4+2
x=6
Vậy x=6
f) ( 17x - 25 ) : 8 + 65 = 92
( 17x - 25 ) : 8 + 65 = 81
( 17x - 25 ) : 8 = 81 - 65
( 17x - 25 ) : 8 = 16
17x - 25 = 16 . 8
17x - 25 = 128
17x = 128 + 25
17x = 153
x = 153 : 17
x = 9
Vậy x=9