Đáp án cần chọn là: A

3 x < x - 2>=60 - 51

3x <x -2>=9

       x - 2 = 9 : 3

      x -2    =  3

          x     = 3 + 2 

          x     = 5

Vậy x = 5

60-3(x-2)=51

3(x-2)=60-51=9

x-2=9:3=3

x=3+2

x=5

\(60-3\left(x-2\right)=51\)

=> \(3\left(x-2\right)=60-51=9\)

=> \(x-2=\dfrac{9}{3}=3\)

=> \(x=5\)

chúc em học tốt!

60 - 3 . (x - 2) = 51

       3 . (x - 2) = 60 - 51

       3 . (x - 2) = 9

             x - 2  = 9 : 3

             x - 2  = 3

                     => x = 1

             Vậy x = 1

a,  70 - 5 ( x - 3 ) = 45

⇔ 5 . x - 3 = 70 - 45

⇔ 5 x - 3 = 35

⇔ x - 3 = 35 : 5 ⇔ x - 3 = 7

⇔ x = 10

b,  10 + 2 x = 4 5 : 4 3

⇔ 10 + 2 x = 4 2 ⇔ 10 + 2 x = 16

⇔ 2 x = 4 ⇔ x = 2

c,  60 - 3 x - 2 = 51

⇔ 3 x - 2 = 60 - 51

⇔ 3 x - 2 = 9

⇔ x - 2 = 3 ⇔ x = 5

d,  4 x - 20 = 2 5 : 2 3

⇔ 4 x - 20 = 2 2 ⇔ 4 x - 20 = 4

⇔ 4 x = 24 ⇔ x = 6

a)x+5=20-5

x+5=15

x=15-5

x=10

b) sai đề

a)x+5=20-(12-7)

x+5=20-5

x+5=15

x=15-5

x=10

b)4*(3*x-4)=18

3*x-4=18:4

3*x-4=4,5

3*x=4,5+4

3*x=8,5

x=8,5:3

x=17/6

c)128-3*x(x+4)=18

3*x(x+4)=128-18

3*x(x+4)=110

4*x+12=110

4*x=110-12

4*x=98

x=98:4

x=24,5

d)60-3*(x-2)=51

3*(x-2)=60-51

3*(x-2)=9

x-2=9:3

x-2=3

x=3+2

x=5

a) \(60-3.\left(x-2\right)=51\)

\(\Rightarrow3.\left(x-2\right)=60-51=9\)

\(\Rightarrow x-2=9:3=3\)

\(\Rightarrow x=3+2=5\)

b) \(\left(105-x\right):2^5=3^{0+1}=3^1=3\)

\(\Rightarrow\left(105-x\right):32=3\)

\(\Rightarrow105-x=3.32=96\)

\(\Rightarrow x=105-96=9\)

c) \(x+5=20-\left(12-7\right)\)

\(\Rightarrow x+5=20-5\)

\(\Rightarrow x+5=15\)

\(\Rightarrow x=15-5=10\)

x=5

đúng nha kagome

60-3(X-2)=51

=>3(X-2)=60-51

=>3(X-2)=9

=>X-2=9:3

=>X-2=3

=>X=3+2

=>X=5

<=> 3.(x - 2) = 60 - 51 = 9

x - 2 = 9 : 3 = 3

x = 3 + 2

x = 5

nha bn

60-3 (x-2) =51

    3(x-2)=60-51

    3(x-2)=9

    (x-2)=9:3

    x-2=3

    x=3+2

    x=5

60-3.(x-2)=51

     3.(x-2)=60-51

     3.(x-2)=9

        x-2  =9:3

        x-2  =3

        x     =3+2

        x     =5