Question

[(6x-39):7].4=12

9.(x+4)-25=5.4mik cần gấp

Answer 1

[(6x-39):7].4=12

(6x-39):7=12:4

(6x-39):7=3

6x-39=7.3

6x-39=21

6x=21+39

6x=60

x=60:6

x=10

9.(x+4)-25=5.4

9(x+4)-25=20

9(x+4)=20+25

9(x+4)=45

x+4=45:9

x+4=5

x=5-4

x=1

Answer 2

`@`\(\left[\left(6x-39\right):7\right].4=12\)

\(\Rightarrow\left[\left(6x-39\right):7\right]=3\)

\(\Rightarrow6x-39=3.7\)

\(\Rightarrow6x=21+39\)

\(\Rightarrow6x=60\)

\(\Rightarrow x=10\)

`@`\(9.\left(x+4\right)-25=5.4\)

`=>9.(x+4)-25=20`

`=>9.(x+4)=20+25`

`=>9.(x+4)=45`

`=>x+4=45:9`

`=>x+4=5`

`=>x=1`

Answer 3

\(\left[\left(6x-39\right):7\right]\cdot4=12\\ \left(6x-39\right):7=12:4\\ \left(6x-39\right):7=3\\ 6x-39=3\cdot7\\ 6x-39=21\\ 6x=21+39\\ 6x=60\\ x=10\)

\(9\left(x+4\right)-25=5\cdot4\\ 9\left(x+4\right)-25=20\\ 9\left(x+4\right)=20+25\\ 9\left(x+4\right)=45\\ x+4=45:9\\ x+4=5\\ x=1\)