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Question

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

2 years ago

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Earnestine Connelly


1 Answer

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Ante R Verified Sherpa Tutor ✓

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


If the coefficients of a variable are the same, the easiest way to solve it is to multiply one equation with -1, and then add that and the other equation together. Since the coefficients of a variable are now opposite, they will add to zero, thereby resulting in a single equation to solve.


Example:


[1] y+2x = 4

[2] -4y+2x = -6 |*(-1)

[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 the same or opposite coefficients of a variable, this method is the easier alternative.

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