Question

What is the solution to the system of equations below?

7x+3y + z = 10
X+-4y - Z=0
2x+6y + 2z = 8
O A. x = 3, y = 8, z =5
O B. X = 3, y = 1, z=7
O c. x = 1, y = -2, z = 9
O D. X = 1, y = -2, z= 7

Answer 1

C: x=1 y=-2 z=9

Explanation:

7x+3y + z = 10 z=10-7x-3y

X+(-4y)-(10-7x-3y)=0

x-4y-10+7x+3y=0

8x-y-10=0

y=8x-10

2x+6(8x-10)+ 2z = 8

2x+48x-60+2z=8

z=10-7x-3(8x-10)

z=10-7x-24x+30

z=40-31x

50x+2z=68

50x+2(40-31x)=68

50x+80-62x=68

-12x=-12 x=1

z=40-31x z=40-31*1 z=9

y=8x-10 y=8*1-10 y=-2

answer: x=1 y=-2 z=9