a, 11 - ( 15 + 11 ) = x - ( 25 - 9 )

11-15-11=x-25+9

-15=x-16

x=1

b, 2 - x = 17 - ( - 5 )

2-x=22

x=-20

c, x - 12 = ( - 9 ) - 15

x-12=-24

x=-12

d, 9 - 25 = ( 7 - x ) - ( 25 + 7 )

(7-x)-32=-16

7-x=16

x=-9

#H

a; - \(\dfrac{10}{13}\) + \(\dfrac{5}{17}\) - \(\dfrac{3}{13}\) + \(\dfrac{12}{17}\) - \(\dfrac{11}{20}\)

= - (\(\dfrac{10}{13}\) + \(\dfrac{3}{13}\)) + (\(\dfrac{5}{17}\) + \(\dfrac{12}{17}\)) - \(\dfrac{11}{20}\)

= - 1 + 1  - \(\dfrac{11}{20}\)

=   0 - \(\dfrac{11}{20}\)

= - \(\dfrac{11}{20}\)

b; \(\dfrac{3}{4}\) + \(\dfrac{-5}{6}\) - \(\dfrac{11}{-12}\)

= \(\dfrac{9}{12}\) - \(\dfrac{10}{12}\) + \(\dfrac{11}{12}\)

= \(\dfrac{10}{12}\)

= \(\dfrac{5}{6}\)

c; [13.\(\dfrac{4}{9}\) + 2.\(\dfrac{1}{9}\)] - 3.\(\dfrac{4}{9}\)

= [\(\dfrac{52}{9}\) + \(\dfrac{2}{9}\)] - \(\dfrac{4}{3}\)

= \(\dfrac{54}{9}\) - \(\dfrac{4}{3}\)

= \(\dfrac{14}{3}\)

d; 1,25 : \(\dfrac{15}{20}\) + [25% - \(\dfrac{5}{6}\)] : 4.\(\dfrac{2}{3}\)

= 1,25  x \(\dfrac{20}{15}\) + [\(\dfrac{1}{4}\) - \(\dfrac{5}{6}\)] : 4.\(\dfrac{2}{3}\)

=  \(\dfrac{5}{3}\) - \(\dfrac{7}{12}\) : 4 x \(\dfrac{2}{3}\)

= \(\dfrac{5}{3}\) - \(\dfrac{7}{48}\).\(\dfrac{2}{3}\)

= \(\dfrac{5}{3}\) - \(\dfrac{7}{72}\)

= \(\dfrac{113}{72}\)

a) x – 32 : 16 = 48 ó x – 2 = 48 ó x = 48 + 2 ó x = 50

b) 88 – 3.(7+x) = 64 ó 3.(7+x) = 88 – 64 ó 7 + x = 24:3 ó x = 8 – 7 ó x = 1

c) (5+4x) : 3 – 121 : 11 = 4 ó (5+4x) : 3 – 11 = 4 ó (5+4x) : 3 = 4 + 11 ó 5+4x = 15.3 ó 4x = 45 – 5 ó 4x = 40 ó x = 10

d) 15 – 2(3x+1) = 11.13 – 130 ó 15 – 2(3x+1) = 143 – 130 ó 15 – 2(3x+1) = 13

ó 2(3x+1) = 15 – 13 ó 3x + 1 = 2:2 ó 3x = 1 – 1 ó 3x = 0 ó x = 0

a)  x = 64 : 8 = 8

b)  x = 60 : − 15 = − 4

c) 

12 x = 30 − 6 12 x = 24       x = 24 : 12       x = 2

d)

− 11 . x = 130 − 9 − 11 . x = 121                x = 121 : − 11                x = − 11

a)  x = 64 : 8 = 8

b)  x = 60 : − 15 = − 4

c) 

12 x = 30 − 6 12 x = 24       x = 24 : 12       x = 2

d)

− 11 . x = 130 − 9 − 11 . x = 121                x = 121 : − 11                x = − 11

Bài 1:

a)(-12)+(+7)+(-3)=-12+7+(-3)=-5+9-3)=-8

b)15+(-9)+(-13)=6+(-13)=-7

c)[(-15)+(-17)]+[(-8)+(+17)]=(-32)+9=-23

d)[12+(-19)]+[11+(-15)]=(-7)+9-4)=-11

Bài 2:

a)13-|x|=11

       |x|=13-11

       |x|=2

Xảy ra hai trường hợp:x=2 và x=-2

a) Ta có: \(x-12=\left(-9\right)-15\)

\(\Rightarrow x-12=-24\)

\(\Rightarrow x=-12\)

b) \(2-x=17-\left(-5\right)\)

\(\Rightarrow2-x=22\)

\(\Rightarrow x=2-22\)

\(\Rightarrow x=-20\)

c) \(11-\left(15+11\right)=x-\left(25-9\right)\)

\(\Rightarrow-15=x-16\)

\(\Rightarrow x=1\)

d) \(x-\left(17-x\right)=x-7\)

\(\Rightarrow x-17+x=x-7\)

\(\Rightarrow x+x-x=-7+17\)

\(\Rightarrow x=10\)

e) \(9-25=\left(7-x\right)-\left(25+7\right)\)

\(\Rightarrow9-25=7-x-25-7\)

\(\Rightarrow-16=-25-x\)

\(\Rightarrow x=-9\)

g) \(x-13=21-x\)

\(\Rightarrow x+x=21+13\)

\(\Rightarrow2x=34\)

\(\Rightarrow x=17\)

a, x - 12 = ( -9 ) - 15 

x - 12 = -24

x = -24 + 12

x = -12

b, 2 - x = 17 - ( -5 )

2 - x = 22

x = 2 - 22

x = -20

c, 11 - ( 15 + 11 ) = x - ( 25 - 9 )

11 - 26 = x - 16

-15 = x - 16

x = -15 + 16 

x = 1

d, x - ( 17 - x ) = x - 7

x - 17 + x = x - 7

x + x - 17 = x - 7

x + x - x = -7 + 17

x = 10

e.9 - 25 = ( 7- x ) - ( 25 + 7 )

-16 = ( 7 - x ) -32

7 - x = -32 + 16 

7 - x = 16

x = 7 - 16

x= -9

g, x - 13 = 21 - x

x + x = 21 + 13

2x = 44

x = 44 : 2

x=22

A= -12

B=-20

C=1

D=17

E=-9

G=17

a) x = 4

b) x = -8

c) | x | - 9 = -2 + 17

| x | = 15 + 9

| x | = 24

x = 24 hoặc x = -24

d) |x – 9| = -2 + 17

|x – 9| = 15

x – 9 = 15 hoặc x – 9 = -15

x = 24 hoặc x = -6

bạn có thể check lại đề bài câu a được không ạ

là x^2 = x^5 á bạn