Math 1 · Unit 6 · Lesson 3 · part 4 of 5
Choosing the easiest method
Three roads to the same point.
Choosing the easiest method
Three roads to the same point. Which one to take?
Graphing: to seeWhen you want the picture, or a rough answer, or a check on what algebra gave you.
Substitution: when a variable is aloney = 3x − 1, or x = y + 4, or a coefficient of 1 that comes free in one step.
Elimination: when the coefficients line upBoth equations in Ax + By = C form, especially when a pair of coefficients is already opposite or equal, or becomes so with one multiplication.
Every method turns two variables into one. Substitution swaps an expression in. Elimination adds to make a zero appear. Both leave a Unit 1 equation.