Answer:
3. See explanation
2.
1.
Explanation:
3. Substitution, Elimination, and Graphing are ALL three methods to solve a system of equations, whether they are in three variables or two. The only differense is that with graphing, you will easily spot when a system is dependent [Infinitive Solutions], inconsistent [no solution], and\or consistent [one solution]. With elimination, you want to eliminate one set of variables [set to zero] so that it will be alot simpler solving the system, then latre on, substitute whatever value solved for the remaining set of variables back into the system to solve for the eliminated variable. Finally, with substitution, all you have to do is choose which variable you want to solve for in all three equations, or two. It really does not matter which one, as long as you follow the proper universal concept in using the Order of Operations.
2. This is self-explanatory really. The only time you cannot use any method is when the linear equations form parallel lines. Otherwise, you will always have one or infinite solutions.
1. See above imagery
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