SOLUTION: Solve each system of quations below using multiplication with the addtion method. 5x-2y=4 3x-2y-5 I dont know how to start it. I think u multiply the top 5x-27=4 by 2, somet

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Solve each system of quations below using multiplication with the addtion method. 5x-2y=4 3x-2y-5 I dont know how to start it. I think u multiply the top 5x-27=4 by 2, somet      Log On


   

Question 190012: Solve each system of quations below using multiplication with the addtion method.
5x-2y=4
3x-2y-5
I dont know how to start it. I think u multiply the top 5x-27=4 by 2, something like that. thats what confuses me the most.
Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!


Given Line Eqnsystem%285x-2y=4%28red%28EQN1%29%29%2C3x-2y=5%28red%28EQN2%29%29%29

*Note in red%28EQN2%29, 3x-2y-5=3x-2y=5

MULTIPLY red%28EQN1%29 by -1

(5x-2y=4)x%28-1%29 = -5x%2B2y=-4, red%28EQN3%29 and ADD red%28EQN2%29:

-5x%2Bcross%282y%29=-4, red%28EQN3%29
+3x-cross%282y%29=5, red%28EQN2%29
----------------
-2x=1 ---> cross%28-2%29x%2Fcross%28-2%29=-1%2F2
highlight%28red%28x=-1%2F2%29%29,subst. in red%28EQN1%29

5%28highlight%28-1%2F2%29%29-2y=4
-5%2F2-2y=4
2y=-5%2F2-4=%28-5-8%29%2F2=-13%2F2
cross%282%29y%2Fcross%282%29=%28-13%2F2%29%2F2
highlight%28red%28y=-13%2F4%29%29

These 2 lines intersect at point (-1/2,-13/4) ---> (-0.50,-3.25)

----> red%28RED=EQN1%29; green%28GREEN=EQN2%29

Thank you,
Jojo