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2 votes
-4x-2y=-12 and 4x+8y=-24 using addition/eliminatin method

User Xster
by
6.7k points

2 Answers

5 votes
elimination method is best because one equation has 4x and the other has -4x. Add the two equations together.

-4x - 2y = -12
+4x + 8y = -24
----------------------
0 + 6y = - 36

divide by 6 both sides
y = -6

use this to find x in either equation.
4x + 8(-6) = -24
4x - 48 = -24
4x = -24 + 48
4x = 24
x = 6

User Chef Gladiator
by
5.9k points
4 votes
Use the elimination method:

-4x - 2y = -12
+4x + 8y = -12
--------------------
0 + 6y = -24

6y = -24
6y/6 = -24/6
y = -4

Plug in -4 for y in one of the equations
-4x - 2y = -12
-4x - 2(-4) = -12
-4x + 8 = -12
-4x + 8 (-8) = -12 (-8)
-4x = -20
-4x/-4 = -20/-4
x = 5

x = 5, y = -4

hope this helps
User Eranga Kapukotuwa
by
6.5k points
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