Question

Solve the system.
x + y - 3z = -20
-3y + 2z = 5
z = 4

Answer 1

x= -9

y= 1

Explanation:

-3y+2z=5

(put the value of z in the equation)

-3y+2(4)=5

-3y+8=5

8-5=3y

3=3y

y=3/3

therefore y= 1

x+y-3z=-20

(put the value of y and z in the equation)

x+1-3(4)=-20

x+1-12=-20

x+1= -20+12

x= -8-1

therefore x= -9

I hope it will help.