What should you do if the coefficients have the opposite sign?

2 years ago


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Ernesto Emmerich

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Assuming this is a question about solving a set of equations.

If the coefficients of a variable are the same, but with the opposite sign in two equations, the easiest way to solve it is to add the two equations together. Since the coefficients of a variable are opposite, they will add to zero, thereby resulting in a single equation to solve.


[1] y+2x = 4

[2] 4y-2x = 6

[1] + [2] 5y+0 = 10

y = 2

2+2x = 4

x = 1

Solution: (1, 2)

Note: there is the usual way of solving any set of equations, (by substituting a variable for its expression), but in cases where you have opposite coefficients of a variable, this method is the easier alternative.

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