help me solve this 3 variable equation using substitution please.

x - 2y + 3z = -7

4x + 5y + z = 4

-x + y - 2z = 5

Question

help me solve this 3 variable equation using substitution please.

x - 2y + 3z = -7

4x + 5y + z = 4

-x + y - 2z = 5

phi · Answer

Do you have to use substitution?  Because elimination is the preferable method.

anonymous · Answer

Solve the first equation for X.
Place that value into the third equation, solve for Y.

Place the value of X into the 2nd equation, then Y into what you get from there.
Solve for Z, then place the value you got for Z into the equation you got for Y. Then place both values into the first equation.

anonymous · Answer

Doesnt matter.:)

phi · Answer

I would learn to do elimination.  It is more "automatic", and gets to the answer with less work.

anonymous · Answer

how do you do the elimenation way?

phi · Answer

make sure the equations have the variables in the same order x,y,z .  Here they are.
then just write down the coefficients:
|dw:1340643399371:dw|