When should you use the addition method to solve a system instead of substitution?

 Apr 29, 2019

You should use the addition method when there are two of the same amount of variables or in a situation where you could easily multiply one equation to get the same amount of variables in the other, like 2 equations both having 4x.

If it is hard, then just use substitution

2x + 4y = 8

4x + 6y = 14

I know this isn't a real linear function, but you can see that you can easily divide the second equation by 2 so that both equations have 2x, then you ocan do the addition method

5x + 3y = 18

17x + 7y = 3

Here, it would take more work to make either x or y be the same value, so you could do the substituion method.

 Apr 29, 2019

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