Answer:
a set of two or more equations, each containing two or more variables whose values can simultaneously satisfy both or all the equations in the set, the number of variables being equal to or less than the number of equations in the set.
Explanation:
It works because of two properties of equations: Multiplying (or dividing) the expression on each side by the same number does not alter the equation. Adding two equations produces another valid equation: e.g. 2x = x + 10 (x = 10) and x − 3 = 7 (x also = 10).