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9x+2y-27z=-155 -11x-y+37z=208 19x+6y-52z=-304

1 Answer

1 vote

Answer:

(x,y,z)=( -2, -1 ,5)

Explanation:

9x+2y-27z=-155 (1)

-11x-y+37z=208 (2)

19x+6y-52z=-304 (3)

(1) *3 ;(2) *6 ;(3)*1, you have

27x+6y-81z=-465 (1)

-66x-6y+222z=1248 (2)

19z+6y-52z=-304 (3)


(1) +(2), you have

-39x+141z= 783 (4)

(4) /3, you have

-13x +47z=261 (4)


(2) +(3), you have

-47x+170z=944 (5)


From ( 4) and (5), you have equations

-13x +47z=261 (4)

-47x+170z=944 (5)


(4)*(-47); (5)*13, you have

611x-2209z=-12,267 (4)

-611x+2210z=12,272 (5)


(4)+(5), you have

z=5

Replace z=5 in (4), you have

611x- 2209*5=-12,267

611x- 11,045 =-12,267

611x=-1222

x= -2

Replace x=-2, z=5 in (1) , you have

9*(-2) +2y -27*5=-155

-18+2y-135=-155

-18+2y=-20

2y=-2

y=-1

Result (x,y,z)=( -2, -1 ,5)









User Matthew Woo
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