These are not equations of lines because there are no
equal signs in the equations.
Assuming the equations
are...
-2x + y = 1
x + y =
5
Set both equations to equal
y.
-2x + y = 1 y = 1 +
2x
x + y = 5 y = 5 -
x
Since both equations equal y, then they equal each
other.
1 + 2x = 5 - x
Solve
for x.
1 + 3x = 5
3x =
4
x = 4/3
Now substitute 4/3
in for x in one of the equations and solve for y.
y = 5 -
x
y = 5 - 4/3
y =
11/3
You can check this by substituting 4/3 for x and 11/3
for y in the other equation.
y = 1 +
2x
11/3 = 1 + 2 * 4/3
11/3 = 1
+ 8/3
11/3 = 11/3
check!
Point of Intersection: (4/3 ,
11/3)
This question can also be solved
graphically. Rewrite both equations in slope-intercept
form.
y = -1x + 5
y = 2x +
1
Graph both equations and find the point of
intersection.
src="/jax/includes/tinymce/jscripts/tiny_mce/plugins/asciisvg/js/d.svg"
sscr="-1,3,-1,5,1,1,1,1,1,300,200,func,-1x+5,null,0,0,,,black,1,none,func,2x+1,null,0,0,,,black,1,none"/>
Notice
that the point of intersection is (4/3, 11/3) or ( class="AM">`~~` 1.3, `~~`
3.7).
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