SOLUTION: I have a dusey for you. My teacher cant explaine it so i can understand it. i need to solve this system of equations with elimination: A: x-2y+3z=4 B: 2x+y-4z=3 C: -3x+4y-z=-2

Algebra ->  College  -> Linear Algebra -> SOLUTION: I have a dusey for you. My teacher cant explaine it so i can understand it. i need to solve this system of equations with elimination: A: x-2y+3z=4 B: 2x+y-4z=3 C: -3x+4y-z=-2       Log On


   



Question 98855: I have a dusey for you. My teacher cant explaine it so i can understand it. i need to solve this system of equations with elimination:
A: x-2y+3z=4
B: 2x+y-4z=3
C: -3x+4y-z=-2
Much appriecated!!!

Answer by malakumar_kos@yahoo.com(315) About Me  (Show Source):
You can put this solution on YOUR website!

solve this system of equations with elimination:
A: x-2y+3z=4
B: 2x+y-4z=3
C: -3x+4y-z=-2
To solve the given eq'ns by elimination we have to first solve A and B then solve Band C and then solve the resulting eq'ns
A: x-2y+3z = 4
B: 2x+y-4z = 3 multiply B by 2 B: 4x+2y-8z = 6
A: x-2y+3z = 4
---------------
5x -5z = 10
--------------
5x-5z = 10 or 5(x-z) = 10 or x-z = 10/5 = 2........(D)
B:2x+y-4z = 3
C:-3x+4y-z = -2 multiply B by 4 B:8x+4y-16z = 12
C: -3x+4y-z = -2
subtracting -11x-15z = 14......(E)
from D substitute for x in (E) we get -11(2+z)-15z = 14
-22-11z-15z = 14
-26z = 14+22 =36
z = -36/26
from (D) x-z = 2
x = 2+z = 2-36/26
= 52-36/26 = 16/26
x = 16/26
substituting for x and z in B we get 2(16/26)+y-4(-36/26)= 3
32/26 +y +144/26 = 3
y + 176/26 = 3
y = 3-176/26
= 78-176/26
= -98/26
the values of x,y and z is x = 8/13, y = -49/13 and z = -18/13