a ) x = 5 4 x = − 5 4 b ) x = 3 2 x = − 1 2 c ) x = 3 2 x = − 1 2

d ) x = 59 40 x = 61 40 e ) x = 1 3 x = − 1 f ) x = 1 3 x = − 1

12 + 21 x 12 + 12 x 34

= 12 x ( 1 + 12 + 34 )

= 12 x 45

= 540

12 + 21 x 12 + 12 x 34

= 12 x 1 + 21 x 12 + 12 x 34

= 12 x (1+21+34)

= 12 x 56

= 672

12+252+408=12+660=672

a ) x − 2 5 : 2 3 = 3 4 x − 2 5 = 3 4 . 2 3 x − 2 5 = 1 2 x = 9 10

b ) x + − 3 4 − 1 2 = 2 3 . 3 5    x + − 3 4 − 1 2 = 2 5 x + − 3 4 = 9 10 x = 33 20

c ) x − 2 7 = − 9 14 . − 4 3 x − 2 7 = 6 7 +)  x − 2 7 = 6 7 x = 8 7 +)  x − 2 7 = − 6 7    x = − 4 7

a) 12+x=34

          x=34-12

          x=22

b) 23+x=34

         x=34-23

         x=11

c)45+34=79

a, 12 + x = 34

x = 34 - 12

x = 22

b, 23 + x = 34

x = 34 - 23

x = 11

c, 45 + 34 = x 

x = 79

a) 12+x=34

           x=34-12

           x=22

b) 23+x=34

           x=34-23

           x=11

c) 45+23=x

    68=x

    x=68

a) 2 + (81 - x) = -34

81 - x = -34 - 2

81 - x = -36

x = 81 - (-36)

x = 81 + 36

x = 117

b) (-12).x = 60

x = 60 : (-12)

x = -5

c) 12 : (x - 1)² = 3

(x - 1)² = 12 : 3

(x - 1)² = 4

(x - 1)² = 2² (cùng số mũ)

⇒ x - 1 = 2

x = 2 + 1

x = 3

2+(81-x)=-34

      81-x=(-34)-2

      81-x=-36

            x=81-(-36)

            x= 117

(-12)x=60

         x=60:(-12)

          x=-5

x + 12 = 46

       x = 46 - 12

       x = 34

x + 12 = 34 + 12

x + 12 = 46

x        = 46 - 12

x        = 34

K mình mình K lại

x + 12 = 34 + 12

x + 12 = 46

x = 46 - 12

x = 34

ai tk mk  mk tk lại

x+12=34+12

x+12=46

x     =46-12

x     =34

x + 12 = 34 + 12

x + 12 = 36

x = 36 - 12

x = 24

Tk mk mk tk lại 

x + 12 = 34 + 12

x + 12 = 36

x = 36 - 12

x = 24

Tk mk mk tk lại 

a.1872

b.3676

2 tui cũng là army yiu bts nhìu 

----jung hosoek---

a) 12 x 13 + 12 x 49 + 12 x 14 +14 x 78 = 1873

b) 34 x 34 + 56 x 45 = 3676

\(1.\text{ Tính : }\)

\(a,\text{ }12\text{ x }13+12\text{ x }49+12\text{ x }14+14\text{ x }78\)

\(=12\text{ x }\left(13+49\right)+14\text{ x }\left(12+78\right)\)

\(=12\text{ x }62+14\text{ x }90\)

\(=744+1260\)

\(=2004\)

\(b,\text{ }34\text{ x }34+56\text{ x }45\)

\(=1156+2520\)

\(=3676\)