How do you solve? 3x + 3y + 2z = –5
x + y + 3z = –4
2x + 2y + 5z = –7

Question

How do you solve? 3x + 3y + 2z = –5 
x + y + 3z = –4 
2x + 2y + 5z = –7

anonymous · Answer

using matrices

anonymous · Answer

can you set up the augmented matrix?

unklerhaukus · Answer

add the second and third equations, and find the difference with the first equation, hence solve for z

anonymous · Answer

or you can do matrices.

callisto · Answer

3x + 3y + 2z = –5    -(1)
x + y + 3z = –4        -(2)
2x + 2y + 5z = –7    -(3)
(2)x(-2) + (2)
-2 (x + y + 3z) + (2x + 2y + 5z) = -2(-4) + (-7)
-z = 1
z= -1
Sub z=-1 into the equations. Solve x and y. If I haven't got that wrong, there should be infinitely many solutions for x and y.

Sorry, I made a mistake in the deleted post.