Câu trả lời:

\(\text{ x - ( -25 - 17 - x ) = 6 + x }\)

\(\Rightarrow x+25+17+x=6+x\)

\(\Rightarrow2x+42=6+x\)

\(\Rightarrow2x-x+42=6\)

\(\Rightarrow x+42=6\)

\(\Rightarrow x=6-42=-36\)