please help me!?

1 ⤊

i cant solve this!
2x-y-z=7
3x+5y+z=-10
4x-3y+2z=4
if u can explain or just me an answer!! thank u!

2007-10-29 14:49:41 · 2 answers · asked by crazyyyCHICK 2 in Science & Mathematics ➔ Mathematics

2 answers

Doing it by substitution is long and messy. Did you study matrix multiplication/division?

2 -1 -1 ? 7
3 5 1 x ? = 10
4 -3 2 ? 4

2007-10-29 14:56:09 · answer #1 · answered by Computer Guy 7 · 0⤊ 0⤋

Add first two to get 5x + 4y = -3
Add doubled first to last :
4x -2y -2z + 4x - 3y+ 2z = 14 + 4
to get 8x - 5y = 18

Now solve the system :
5x + 4y = -3
8x - 5y = 18

2007-10-29 21:59:47 · answer #2 · answered by Don E Knows 6 · 1⤊ 0⤋