11- (x+84) = 97
=> 11 -x - 84 = 97
=> 11-x = 181
=> x= 11- 181
=> x= -170
cấc câu sau làm tương tự
11 - (x + 84) = 97
x + 84 = 11 - 97
x + 84 = -86
x = -86 - 84
x = -170
-(x + 84) + 213 = -16
-x - 84 = -16 - 213
-x - 84 = -229
-x = -229 + 84
-x = -145
x = 145
x + (-35) = 18
x - 35 = 18
x = 18 + 35
x = 53
-2x -(-17)= 15
-2x + 17 = 15
-2x = 15 - 17
-2x = -2
x = -2 : (-2)
x =1
a,11-(x+84)=97
11-x-84 =97
11-x =97+84
11-x =181
x =11-181
x =-170
b,-(x+84)+213=-16
-x-84+213 =-16
-x-84 =-16-213
-x-84 =-229
-x =-229+84
-x =-145
x =145
c,x+(-35)=18
x-35 =18
x =18+35
x =53
d,-2x-(-17)=15
-2x+17 =15
-2x =15-17
-2x =-2
-x =-2:2
-x =-1
x =1