2x+2z=4
is
z = 2 - x
then
-x-y-z=-8
is
- x - y -2 + x = -8
or
-y = -6
which is y = 6
-4x+4y+5z=7
is
-4x + 24 +5(2-x) = 7
-4 x + 34 -5 x = 7
- 9 x = -27
x = 3
now go back and get z
solve the system by substitution.
-x-y-z=-8
-4x+4y+5z=7
2x+2z=4
please help ;-;
1 answer
1 answer