Solve the following system of equations.

x + 4y + z = -10
3x - 3y + 6z = -21
x + 2y + 2z = -10

(1, -2, -3)
(-4, -1, -2)
(-3, -2, -3)
(2, -2, -4)

Question

Solve the following system of equations.

x + 4y + z = -10
3x - 3y + 6z = -21
x + 2y + 2z = -10
 	
	(1, -2, -3)
	(-4, -1, -2)
	(-3, -2, -3)
	(2, -2, -4)

zzr0ck3r · Answer

linear algebra?

zzr0ck3r · Answer

you can make a matrix and reduce it, but I would just check the answers to see which once works......

mathmate · Answer

Add all equations to give
5x+3y+9z=-41

A: 5(1)+3(-2)+9(-3)=-28  not the right one.
B: 5(-4)+3(-1)+9(-2)=?
C: 5(-3)+3(-2)+9(-3)=?
D: 5(2)+3(-2)+9(-4)=?
Continue with ALL the other choices.  
There may be more than one that fits the bill. If that happens, check each individually.