a) -(x-6)=18

-x+6=18

-x=12

a) -18-(x-6)=0

          x-6=(-18)-0

          x-6=-18

          x   = (-18)+6

          x   = -12

b) 29-(10+29)=x-(27-9)

   29-39        = x-18

     -10         =x-18

     x-18=-10

     x    = (-10)+18

     x    = 8

Học tốt

Trl:

a) \(-18-\left(x-6\right)=0\)

\(\Rightarrow\left(x-6\right)=-18-0\)

\(\Rightarrow\left(x-6\right)=-18\)

\(\Rightarrow x=-18+6\)

\(\Rightarrow x=-12\)

b) \(29-\left(10+29\right)=x-\left(27-9\right)\)

\(\Rightarrow29-39=x-18\)

\(\Rightarrow-10=x-18\)

\(\Rightarrow x=18+\left(-10\right)\)

\(\Rightarrow x=28\)

a/ => 2 - x = 22 => x = -20

b/ => x - 12 = -24 => x = -12

c/ => 11 - 26 = x - 16

   => -15 = x - 16

   => x = 1

d/ => 5x - x - 2 + 6x - 10 = 0

  => 10x - 12 = 0

  => 10x = 12

  => x = 1,2

a) 2 - x = 17 - ( - 5)

2 - x = 22

x = 2-22

x=-20

a) \(3x-10=2x+13\Leftrightarrow x=13+10=23\)

b) \(x+12=-5-x\Leftrightarrow2x=-17\Leftrightarrow x=-\frac{17}{2}\)

c) \(x+5=10-x\Leftrightarrow2x=5\Leftrightarrow x=\frac{5}{2}\)

d) \(6x+23=2x-12\Leftrightarrow4x=-35\Leftrightarrow x=-\frac{35}{4}\)

e) \(12-x=x+1\Leftrightarrow2x=11\Leftrightarrow x=\frac{11}{2}\)

f) \(14+4x=3x+20\Leftrightarrow x=20-14=6\)

g) \(2\left(x-1\right)+3\left(x-2\right)=x-4\Leftrightarrow2x-2+3x-6=x-4\)

\(\Leftrightarrow5x-8=x-4\Leftrightarrow4x=4\Leftrightarrow x=1\)

h ) \(3\left(4-x\right)-2\left(x-1\right)=x+20\Leftrightarrow12-3x-2x+2=x+20\)

\(\Leftrightarrow14-5x=x+20\Leftrightarrow6x=-6\Leftrightarrow x=-1\)

i ) \(4\left(2x+7\right)-3\left(3x-2\right)=24\Leftrightarrow8x+28-9x+6=24\)

\(\Leftrightarrow34-x=24\Leftrightarrow x=34-24=10\)

k) \(3\left(x-2\right)+2x=10\Leftrightarrow3x-6+2x=5x-6=10\)

\(\Leftrightarrow5x=10+6=16\Leftrightarrow x=\frac{16}{5}\)

Tự KL cho các phần

a) \(\Rightarrow72-20x-36x+84=30x-240-6x-84\)

\(\Rightarrow80x=480\Rightarrow x=6\)

b) \(\Rightarrow15x+25-8x+12=5x+6x+36+1\)

\(\Rightarrow4x=0\Rightarrow x=0\)

c) \(\Rightarrow10x-16-12x+15=12x-16+11\)

\(\Rightarrow14x=4\Rightarrow x=\dfrac{2}{7}\)

a) -84 - (-18 - 6) = x + (-20)

      -84 + 18 + 6 = x - 20

    -84 + 18 + 6 + 20 = x

                         => x = -40

\(-84-\left(-18-6\right)=x+\left(-20\right)\)

\(\Leftrightarrow x=\left(-20\right)+84+\left(-18-6\right)\)

\(\Leftrightarrow x=40\)

P/s tham khảo nha

a)x=9

b) x=20

c) x=26

d) x=1

A)

\(-14-7+x=-12\)

\(\Leftrightarrow x=-12+7+14\)

\(\Leftrightarrow x=9\)

P/s tham khảo nha

B)

\(x+\left(-15\right)-\left(-6\right)=11\)

\(\Leftrightarrow x=11+\left(-6\right)-\left(-15\right)\)

\(\Leftrightarrow x=20\)

P/s tham khảo nha

a, 60

b, 15

c, 11

d, 11

e, 110

g, 5

a (x-12)+48=96

x-12=96-48=48

x=12+48=60

b56-(17+x)=24

17+x=56-24

17+x=32

x=31-17=15

c 5x+57=112

5x=112-57=55

x=11

d 87-2x=65

2x=87-65=22

x=11

e (x-46):32=2

x-46=64

x=110

g 120-3(x+1)=102

3(x+1)=120-102=18

x+1=6

x=5

a: Ta có: \(\left(x-12\right)+48=96\)

\(\Leftrightarrow x-12=48\)

hay x=60

b: ta có: \(56-\left(x+17\right)=24\)

\(\Leftrightarrow x+17=32\)

hay x=15

c: Ta có: \(5x+57=112\)

\(\Leftrightarrow5x=55\)

hay x=11

d: Ta có: 87-2x=65

\(\Leftrightarrow2x=22\)

hay x=11