Question

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

Answer 1

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

3(x + 2).7      = 120 : 4

3(x + 2)         = 30 : 7

x + 2             = \(\frac{30}{7}:3\)

x                  = \(\frac{10}{7}-2\)

x                  = \(\frac{5}{7}\)

Answer 2

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

\(\Rightarrow3\left(x+2\right)=120:4:7=\frac{30}{7}\)

\(\Rightarrow x+2=\frac{30}{7}.\frac{1}{3}=\frac{10}{7}\)

\(\Rightarrow x=\frac{10}{7}-2=-\frac{4}{7}\)

Answer 3

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

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

=>3(x+2) = 30:7=30/7

=>x+2=30/7:3=10/7

=>x=10/7-2=-4/7

Answer 4

[3(x+20).7].4=120

=> 3(x+20).7=30

=> x+20        =30/21

=> x              =-130/7

Vậy x = -130/7