Question

\(\dfrac{x-12}{5}\)= 4         \(\dfrac{x+8}{7}\)=2                       \(\dfrac{15}{x+2}\)=3

tìm x

 

Answer 1

`[x-12]/5=4`

`x-12=4xx5=20`

`x=20+12`

`x=32`

 

`[x+8]/7=2`

`x+8=7xx2=14`

`x=14-8`

`x=6`

 

`15/[x+2]=3`

`15=3xx(x+2)`

`15=3xx x+3xx2`

`3xx x+6=15`

`3xx x=15-6=9`

`x=9:3=3`

Answer 2

`a, x - 12 = 20`

`-> x = 32`

`b, x + 8 = 14`

`-> x = 6`

`c, 15 = 3x + 6`

`-> 3x = 9`

`-> x =3`

Answer 3

\(\dfrac{x-12}{5}=4\)

x-12=20

x=32

b) x=16