Eliminate

Eliminate[eqns, vars] eliminates variables between a set of simultaneous equations.

Examples

Eliminate y from two equations:

Eliminate[{x + y == 3, x - y == 1}, y]
(* x == 2 *)

Eliminate multiple variables:

Eliminate[{a == b + c, b == 2c, c == 3}, {b, c}]
(* a == 9 *)

Please visit the official Wolfram Language Reference for more details.