Final answer:
The substitution method is used to solve a system of linear equations by replacing one variable with another, offering greater accuracy than the graphical method which is limited by the precision of the drawing.
Step-by-step explanation:
The method used to solve a system of linear equations by replacing one variable with another is the substitution method. In this approach, you solve one of the equations for one variable and then substitute that expression into the other equation. This allows you to have an equation with a single variable, which can then be solved. Once you've found the value of one variable, you can substitute it back into one of the original equations to find the value of the second variable.
Analytical techniques, such as the substitution method among others, are often considered to be more accurate than the graphical method for solving systems of linear equations. This is because the graphical method relies on the precision of the plotting and the ability to accurately determine the coordinates of the intersection point, which can be especially challenging when dealing with decimal or fractional values. In contrast, analytical methods provide exact numerical solutions.