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| Question 166353:  Solve by elimination.
 -3+2y-5z=-3
 3x-y+3z=4
 3x+5y-8z=6
 Answer by elima(1433)
      (Show Source): 
You can put this solution on YOUR website! -3+2y-5z=-3 3x-y+3z=4
 3x+5y-8z=6
 We will take two of the equations, add them together to eliminate a variable;
 -3x+2y-5z=-3
 + 3x-y+3z=4
 ------------
 y-2z=1
 =================
 Now take two other equations and add together to eliminate a variable;
 -3x+2y-5z=-3
 + 3x+5y-8z=6
 -------------
 7y-13z=3
 ===========================
 Now add these two together to eliminate a variable;put first we will need to multiply the first equation by -7 so we will be able to eliminate;
 -7(y-2z=1)
 -7y+14z=-7
 Now we add;
 -7y+14z=-7
 + 7y-13z=3
 -----------
 z=-4
 =============================
 Now we have our z, so we use that in one of the new equations to find y;
 y-2(-4)=1
 y+8=1
 y=-7
 ================================
 We have our y and z so lets plug those values into one of the original equations to find x;
 3x-(-7)+3(-4)=4
 3x+7-12=4
 3x-5=4
 3x=9
 x=3
 Hope you got all of that
 :)
 
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