Question

Penyelesaian sistem persamaan 3x - 2y + z=12 ,2x + y - z =–5, 5x -4y + 2z = 23 adalah x,y, dan z , nilai dari 4x-3y + 5z=..

Answer 1

3x-2y+z=12
2x+y-z = -5
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5x-y. =7.......1
2x+y-z=-5. =>(x2) 4x+2y-2y=-10
5x-4y+2z=23 =>(x1). 5x-4y+2z=23
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9x-2y=13.....2

1&2
9x-2y=13=>(x1) 9x-2x=13
5x-y=7===>(x2) 10x-2y=14
. ------------ . x=1
5x-y=7;5.1-y=7; 5-y=7; y=-2
3x-2y+z=12; 3.1-2(-2)+z=12;
3+4+z=12; z=5
jadi 4x-3y+5z=4.1-3(-2)+5.5=35