Use elimination to solve the system of equations

-3x+ y + 7z = -20
5x - 2y - z = 34
-x + y +4z = -8

Question

Use elimination to solve the system of equations

-3x+ y + 7z = -20
5x  - 2y - z   = 34
-x  + y  +4z  = -8

anonymous · Answer

(use matrices)

anonymous · Answer

oops...sorry...I started to do the elimination method....I am not good with matrices

amigatour · Answer

I hope you can see and understand my writing. I didn't explain it. I just answer the problem. However, watch this video https://www.khanacademy.org/math/trigonometry/systems_eq_ineq/fancier_systems_precalc/v/systems-of-three-variables . It will help you.

amigatour · Answer

x= -4, z= 0.  Plug them to the original equations to find the value of y.

amigatour · Answer

Usually, the addition and subtraction are use in elimination method. Remember the opposite of -  or + ?