Question

a method of solving a system of equations that involves adding equations to remove a variable is called system of equations substitution elimination

Explanation:

To solve a system of equations, the elimination method works by adding (or subtracting) equations to eliminate one variable, which matches the description. "System of equations" is the set of equations, not a method. "Substitution" involves replacing a variable with an expression, not adding equations to remove a variable.

Answer:

elimination