substitution is a poor choice for your equations,
elimination is the obvious way to go
add 1st and 2nd --> -z = 7
z = -7
sub that into 2nd --> -x - y = 9
sub z=-7 into 3rd --> -x + y = 25 (I will assume the 32 is a typo, and you meant 3z )
now add these last two equations
-2x = 34
x = -17
sub into -x-y=9
17 -y = 9
-y = -8
y = 8
x=-17
y= 8
z=-7
subsitution with 3 equations (solve for x,y,z)
x+y-2z=5
-x-y+z=2
-x+y+32=4
1 answer
1 answer