Analisis Kesalahan dalam Menyelesaikan Soal Cerita Sistem Persamaan Linier Tiga Variabel pada Siswa Kelas X MAN 1 Sukoharjo Tahun Ajaran 2017/2018

The object of this research is to describe student’s wrong in solvingmathematic question of the three variable linear equations X class MAN 1 Sukoharjo in2017/2018 years. This research used descriptivequalitative method. Technique of collecting data by test method, interviewand documentation. The data validity investigation used triangulationmethod, is by collecting different data to get data from the same sourcethrough tests, interviews and documentation. Technique of analyzing datathrough data reduction phase, data presentation and conclusion. Based onthe analysis data and discussion student experience errors are: transformation error or Transformation Error of 19,23% is error becausestudents wrong in changing the information presented into mathematicalsentence, the error of process skill or Process Skill Error of 75% is errorbecause students wrong the mathematical procedure and arithmeticoperating, error of writing final answer or Encoding Error of 50% that iserror because students are not writing conclusion from the solusion by theresult, and comprehension error or Comprehension Error of 11,54% that is error because students wrong on identifying problem into the mathematical concepts and commands misunderstand also the question of the questioner