Analysis of Class X Students’ Reasoning Ability in Solving Linear Equation System of two Variables

„Reasoning ability‟ is an aspect of knowledge which often is less paid of attention by teachers. It is a necessary skill for students to figure out the subjects or mathematical concepts. Many students, in fact, have an arduous situation when they attempt to comprehend with those kind of mathematical equipments. The impact of it is that the students merely learn mathematics insignificantly or obtain inadequate understanding particularly in solving mathematics problems. Based on the teachers information, one material considered most difficult is „Linear Equation System of Two Variables‟. Numerous students are having a difficulty in creating the systems of linear equations which made up of two or more variables such that all the equations in the system are considered simultaneously. Thus this research was conducted to see how the reasoning abilities of students of grade X in accomplishing the system of linear equations in two variables. This study is descriptive qualitative research in which three participants were taken from students with different level of ability such as high-ability, medium-skill, and low-ability. The reasoning skills wereexplored through descriptive analysis on the test results of students reasoning ability. According to the data analysis, the researchers concluded that the high-ability student can analyze mathematical situations using appropriate patterns, compile valid arguments, draw logical conclusions, and provide the correct reasons. While in contrast, medium and low-ability student cannot propose valid conclusions from the given problem, so the reasoning indicator used in this research is not fulfilled. Keywords - Reasoning Ability, Linear Equation System of Two Variables.