What is the value of x in the solution of this system?
-3x-y+2z = 7
2y+z= -5
3x+6y= -21
4
2
1
3
2 answers
thx :)
add the 1st and 3rd
5y + 2z = -14
from the 2nd: z = -2y-5
plug into 5y + 2z = -14
5y + 2(-2y-5) = -14
y = -4
into the 3rd:
3x -24 = -21
3x =3
x = 1
btw: z = 3
5y + 2z = -14
from the 2nd: z = -2y-5
plug into 5y + 2z = -14
5y + 2(-2y-5) = -14
y = -4
into the 3rd:
3x -24 = -21
3x =3
x = 1
btw: z = 3