Question 1092376: X+y+z+=8
-x-y+2z=-4
3x+5y-7z=14
2x-3y+z=-1
X+4y+5=25
3x-4y+z=2
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! X+y+z+=8
-x-y+2z=-4
3x+5y-7z=14
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x+y+z+=8
-x-y+2z=-4
3z=4
z=(4/3)
can also multiply the top by -3 to get -3x-3y-3z=-24
add it to ===================== 3x+5y-7z=14
That is 2y-10z=-10
but z+(4/3), so 2y-40/3=-30/3
2y=10/3; y=5/3
substitute into second -x-5/3+8/3=-12/3
-x=-5
x=5
That works in all 3 equations (5, 5/3, 4/3)
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2x-3y+z=-1
X+4y+5z=25; I edited a z in
3x-4y+z=2
determinant of the coefficients of the variables is -10
put the constants in for x and divide that matrix determinant by -10 to get x, which is 8.7 (-87/-10
same for y , which is 5.7
and for z, which is -1.3
Check (8.7, 5.7, -1.3) ANSWER
17.4-17.1-1.3=-1
8.7+22.8-6.5=25
26.1-22.8-1.3=2
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