a) ( x - 17 ) : 21 - 3 = 7

    ( x - 17 ) : 21      = 7 + 3

    ( x - 17 ) : 21      = 10 

      x - 17              = 10 x 21

      x - 17              = 210

      x                     = 210 + 17

      x                     = 227

a) (x - 17) : 21 - 3 = 7

(x - 17) : 21 = 7 + 3

(x - 17) : 21 = 10

x - 17 = 10 x 21

x - 17 = 210

x = 210 + 17

x = 227

Vậy x = 227

Câu b mk ko hiểu

\(5^{x-1}-13=612\)

\(\Leftrightarrow5^{x-1}=625\)

\(\Leftrightarrow5^{x-1}=5^4\)

\(\Leftrightarrow x-1=4\)

\(\Leftrightarrow x=5\)

5^x-1 - 13 = 612

5^x-1 = 612 + 13

5^x-1 = 625

5^x-1 = 5⁴

x+ 1 = 4

x = 4 - 1

x = 3

5x - 13 = 612

5x = 612 + 13

5x = 625

x = 625 : 5

x = 125

Vậy x = 125

5x-1-13=612

5x-1=612+13

5x-1=625

5x=625+1

5x=626

x=626:5

x=125,2

5^x-1 - 13 = 612

5^x-1 = 612 + 13

5^x-1 = 625

5^x-1 = 5⁴

x - 1 = 4

x = 4 - 1

x = 3

Vậy x = 3

5^x+1 = 612 + 13

5^x+1 = 625 = 5⁴

=> x + 1 = 4

=> x = 3

315 + (146 - x)  = 472

          146 - x    =  472 - 315

           146 - x    =  157

                    x    =  146 - 157

                    x        =  -11

5x - 8 = 612

5x        = 612 + 8

5x        =  620

  x        = 620 : 5

  x       =   124

132 : x  = 23 - 12

132 : x   =  11

         x = 132 : 11

         x      =  12

* \(315+\left(146-x\right)=472\)

\(-x=472-315-146\)

\(-x=11\Rightarrow x=-11\)

* \(5x-8=612\)

\(5x=612+8\)

\(5x=620\)

\(x=620:5=124\)

* \(132:x=23-12\)

\(132:x=11\)

\(x=132:11=12\)

(Nhớ k cho mình với nhá!)

a) 315+(146-x)=472

                     146-x=472-315

                     146-x=157

                            x=146-157

                            x=-11

Vậy x=-11

b)5x-8=612

           5x=612+8

           5x=620

             x=620:5

             x=124

Vây x=124

c)132:x=23-12

          132:x=11

                x=132:11

                x=12

Vậy=12

a: =>x=5/6-3/4=10/12-9/12=1/12

b: =>x=12-3/5=57/5

c: =>x=3/5+5/7=21/35+25/35=46/35

d: =>x=7/9:3=7/27

e: =>x=7/8x12/5=84/40=21/10

f: =>x=13:5/3=39/5

5^x+3 -13=612

5^x+3 =612+13

5^x+3 =625

5^x+3 =5⁴

=>x+3=4

x=4-3

x=1

5^x+3-13=612

=> 5^x+3=612+13

=> 5^x+3=625

=> 5^x+3=5⁴

=> x+3=4

=> x=4-3

=> x=1

a: x=192

b: =>5x=612+14=626

hay x=626/5

5^x - 1 - 13 = 612

5^x  = 612 + 13 + 1

5^x  = 626 

x =  4

thay x = 4

5⁴ - 1 - 13 = 612

đúng !

x=612 nhé bạn

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