Question

Solve each by substitution
3x + y - 2z = 22
X + 5y + z = 4
X= -3z

Answer 1

3x+y-2z=22
x+5y+z=4
x=-3z

3(-3z)+y-2z=22
-9z+y-2z=22
-11z+y=22

-3z+5y+z=4
-2z+5y=4

-11z+y=22
-2z+5y=4

-55z+5y=110
--2z+5y=4
----------------------
-53z=106

z=2

-2(2)+5y=4
-4+5y=4
5y=8
y=1.6

x=-3(2)
x=-6

x=-6
y=1.6
z=2