A = { 0 } 

|1/2+1/5+x|=-1/4

|7/10+x|=-1/4

|0,7+x|=-0,25

Vì |0,7+x| > or = 0

     -0.25<0

=>x E {rỗng}

|x-5/3| < 1/3

=>x-5/3 < +- 1/3

=>\(\orbr{\begin{cases}x-\frac{5}{3}=\frac{1}{3}=>x=\frac{1}{3}+\frac{5}{3}=\frac{6}{3}=2\\x-\frac{5}{3}=-\frac{1}{3}=>x=-\frac{1}{3}+\frac{5}{3}=\frac{4}{3}\end{cases}}\)

=> x E {2;-4/3}