Question

a, 720 : ( x - 17 ) = 12

b, 26 + 8x = 6x + 46

c, ( x - 28 ) : 12 = 8

d, 3 ( x - 6 ) - 11 = 22

e, 5 ( x + 2 ) + 8 = 23

f, 4x - 15 - 5 = 20

Answer 1

a, 720 : ( x - 17 ) = 12

=> x - 17 = 720 : 12 = 60

=> x = 60 + 17 = 77

Answer 2

\(a,\text{ }720\text{ : }\left(x-17\right)=12\)

                 \(\left(x-17\right)=720\text{ : }12\)

                  \(\left(x-17\right)=60\)

                                    \(x=60+17\)

                                    \(x=77\)

Answer 3

b, 26 + 8x = 6x + 46

=> 8x - 6x = 46 - 26

=> 2x = 20

=>x = 20: 2 =10

Answer 4

\(b,\text{ }26+8x=6x+46\)

      \(\Rightarrow\text{ }2x=46-26\)

             \(2x=20\)

                \(x=20\text{ : }2\)

                \(x=10\)

Answer 5

\(c,\text{ }\left(x-28\right)\text{ : }12=8\)

      \(\left(x-28\right)=8\text{ x }12\)

      \(\left(x-28\right)=96\)

                        \(x=96+28\)

                        \(x=124\)

Answer 6

\(d,\text{ }3\left(x-6\right)-11=22\)

     \(3\left(x-6\right)=22+11\)

     \(3\left(x-6\right)=33\)

        \(\left(x-6\right)=33\text{ : }3\)

        \(\left(x-6\right)=11\)

                       \(x=11+6\)

                      \(x=17\)

Answer 7

a) 77

b) 10

c) 124 

d) 17

e) 5

f) 10

chúc bạn học tốt

Answer 8

c, ( x - 28 ) : 12 = 8

=> x - 28 = 8 x 12 = 96

=> x = 96 + 28 = 124

Answer 9

3 ( x - 6 ) - 11 = 22

=> 3(x - 6 ) = 22+11=33

=> x - 6 = 33:3=11

=> x = 11+6=17

Answer 10

e, 5 ( x + 2 ) + 8 = 23

=> 5 ( x + 2 ) = 23 - 8 = 15

=> x + 2 = 15 : 5 = 3

=>x = 3 -2 =1

Answer 11

f, 4x - 15 - 5 = 20

=> 4x = 20 + 15 + 5

=> 4x = 20

=> x = 20 :4 = 5

Answer 12

a)  \(720:\left(x-17\right)=12\)

\(\Leftrightarrow\)          \(x-17=60\)

\(\Leftrightarrow\)                     \(x=77\)

Vậy......

Answer 13

b)        \(26+8x=6x+46\)

\(\Leftrightarrow\)\(8x-6x=46-26\)

\(\Leftrightarrow\)            \(2x=20\)

\(\Leftrightarrow\)              \(x=10\)

Vậy.............

Answer 14

c)  \(\left(x-28\right):12=8\)

\(\Leftrightarrow\)      \(x-28=96\)

\(\Leftrightarrow\)                  \(x=124\)

Vậy..........

Answer 15

d)  \(3\left(x-6\right)-11=22\)

\(\Leftrightarrow\)      \(3\left(x-6\right)=33\)

\(\Leftrightarrow\)               \(x-6=11\)

\(\Leftrightarrow\)                        \(x=17\)

Vậy........

Answer 16

e)  \(5\left(x+2\right)+8=23\)

\(\Leftrightarrow\)    \(5\left(x+2\right)=15\)

\(\Leftrightarrow\)            \(x+2=3\)

\(\Leftrightarrow\)                     \(x=1\)

Answer 17

f)  \(4x-15-5=20\)

\(\Leftrightarrow\)  \(4x-20=20\)

\(\Leftrightarrow\)              \(4x=40\)

\(\Leftrightarrow\)                \(x=10\)

Vậy.....

Answer 18

\(a,720:\left(x-17\right)=12\)

\(\Rightarrow x-17=720:12=60\)

\(\Rightarrow x=60+17=77\)

Answer 19

\(b,26+8x=6x+46\)

\(\Rightarrow8x-6x=46-26\)

\(\Rightarrow2x=20\)

\(\Rightarrow x=20:2=10\)

Answer 20

\(c,\left(x-28\right):12=8\)

\(\Rightarrow x-28=8.12=96\)

\(\Rightarrow x=96+28=124\)

Answer 21

\(d,3\left(x-6\right)-11=22\)

\(\Rightarrow3\left(x-6\right)=22+11=33\)

\(\Rightarrow x-6=33:3=11\)

\(\Rightarrow x=11+6=17\)

Answer 22

\(e,5\left(x+2\right)+8=23\)

\(\Rightarrow5\left(x+2\right)=23-8=15\)

\(\Rightarrow x+2=15:5=3\)

\(\Rightarrow x=3-2=1\)

Answer 23

\(f,4x-15-5=20\)

\(\Rightarrow4x=20+15+5=40\)

\(\Rightarrow x=40:4=10\)