Example

Choosing the Most Convenient Method for {3x+8y=40,  7x4y=32}\{3x + 8y = 40,\; 7x - 4y = -32\} and {5x+6y=12,  y=23x1}\{5x + 6y = 12,\; y = \frac{2}{3}x - 1\}

For each system of linear equations, deciding whether substitution or elimination is more convenient depends on the form of the equations. Consider the first system, {3x+8y=40,  7x4y=32}\{3x + 8y = 40,\; 7x - 4y = -32\}. Both of these equations are written in standard form (Ax+By=CAx + By = C) with neither variable isolated. Because they are in standard form, the elimination method is the most appropriate and convenient choice. Next, consider the second system, {5x+6y=12,  y=23x1}\{5x + 6y = 12,\; y = \frac{2}{3}x - 1\}. The second equation is already completely solved for the variable yy. Since one variable is isolated, the substitution method will be the most straightforward approach to use.

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Updated 2026-04-24

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