Question

[ 3 .( x  + 2 ) : 7 ] . 4 = 120

Answer 1

\(\left[3.\left(x+2\right):7\right].4=120\)

\(\Leftrightarrow\left[3.\left(x+2\right):7\right]=30\)

\(\Leftrightarrow3.\left(x+2\right)=210\)

\(\Leftrightarrow\left(x+2\right)=70\)

\(\Leftrightarrow x=68\)

Vậy \(x=68\)

Answer 2

[3.(x+2):7]=120:4=30

3.(x+2)=30x7=210

x+2=210:3=7

x=7-2

x=5

vậy x =5