systems with 3 variables

[hnk4ever15]

i need some help with one of my math problems.....it is x+5y+5z=-10
x+ y+ z=2
x + 2y+ 3z=-3

 

[stapel]

What method(s) have you learned for solving systems of linear equations? Are you using Cramer's Rule, matrix row operations, Gaussian elimination, or something else? How far have you gotten?

Eliz.

 

[hnk4ever15]

ive learned to eliminate one of the variables n then solve it

 

[Denis]

ive learned to eliminate one of the variables n then solve it

Well, if you've really LEARNED that, then why are you having a problem?

 

[stapel]

Each of the equations has "x" by itself (that is, with no coefficient other than "1"), so solve any one of them for "x=", and substitute into the other equations. This will get you down to two equations in two unknowns. Pick one of the equations, and solve for one of the variables. Substitute into the last equation, solve for the last variable, and then work backwards.

Please reply showing where you are stuck. Thank you.

Eliz.