f) 11.(x+2)=5.x+40
=> 11x+22=5x+40
=> 6x=18
=> x=18:6=3
g)11.(x-6)=4.x+11
=> 11.x+(-66)=4x+11
=> 7x=77
=> x=77:7=11
h) (3x-4):x+10=12
=> 3x:x-4:x=12-10=2
=> 3-4:x=2
=> 4:x=3-2=1
=> x=4:1=4
k)(5x+7):x+20=26
=> 5x:x+7:x=26-20=6
=> 5+7:x=6
=> => 7:x=6-5=1
=> x=7:1=7
m) x.1999-x=1999.1997+1999
=> x.1998=1999.(1997+1)
=> x.1998=1999.1998
=> x=1999
**** cho mik nha Nguyễn Thị Thảo Ly
f/ 11x(X+2) = 5xX + 40
g/ 11x(X-6) = 4xX + 11
h/ (3xX - 4) : X + 10 = 12
k/ (5xX + 7) : X + 20 = 26
m/ Xx1999 - X = 1999x1997+1999
Xx1999-X=1999x1997+1999
( 5xX+7):2= 16 128 - 3 x(X - 4)=23 [ (4xX+28) x 3+55 ] :5=35
Bài 6: Tìm X biết :
a) X : [(1800+600) :30] = 560 : (315-35)
b) [(250-50) : 15] : X = (450-60) :130
c) (158- X) : 7 = 20
d) 231-(X - 6) = 1339:13
e) 70-5 (2xX-3) = 45
f)156 - (x +61) = 82
g) 6x(5xX+35) = 330
h) 936 - (4xX +24) =72
Tìm x biết:
11x(X-6)-4xX=11
a) -12+(x-9)<0 tìm x thuộc Z
b)x-(13-x)=-24+(-7+x)
c) (x - 7)+( 5-x)=12-(-8+x)
d)5(x-6)-2(x+3)=12
e)3(x-4)-(8-x)=12
f) 7(x-3)-5(3-x)=11x-5
g) 7(x-9)-5(6-x)=-6+11x
a) -12+(x-9)<0 tìm x thuộc Z
b)x-(13-x)=-24+(-7+x)
c) (x - 7)+( 5-x)=12-(-8+x)
d)5(x-6)-2(x+3)=12
e)3(x-4)-(8-x)=12
f) 7(x-3)-5(3-x)=11x-5
g) 7(x-9)-5(6-x)=-6+11x
