Question 194909
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Remember that a linear equation is a rule that describes a set of ordered pairs, the coordinates of which make the equation a true statement.  So, if you don't have a y variable, such as in x = 3, then you are describing the set of ordered pairs where 3 is always the x coordinate, and the y coordinate can be anything -- in other words, a vertical line that intersects the x-axis at (3,0).


If there is no x variable, then you have a horizontal line.


For the system:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ x + 3y = 9]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ x = 3]


You are given the value of x, so just substitute it into the first equation:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 3 + 3y = 9]


And solve for y.



John
*[tex \LARGE e^{i\pi} + 1 = 0]
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