How do you solve the following linear system: y=−x+4,3x+y=−2?

1 Answer
EZ as pi
Mar 11, 2018

x=−3andy=7

Explanation:

This is one of the best forms you can have for a system of equations. Note that they each have a single y term...

Graphically it means they each represent a straight line and the solution is the point of intersection of the lines.

Write each equation in slope-intercept form, ie with y on one side.

y=−x+4 and y=−3x−2

Now, as y=y, equate the right sides of the equations:

−x+4=−3x−2

3x−x=−2−4

2x=−6

x=−3

Now you can use one equation to find a value for y and the
other equation to check.

y=−(−3)+4 and y=−3(−3)−2
y=3+4wwwwwwwwwwww.wy=9−2
y=7wwwwwwwwwwwwwwwwy=7

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