Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to solve matrices [title] Verify that you have sufficient data. [step] In order to get a unique solution for each variable in a linear system using a matrix, you need to have as many equations as the number of variables that you are trying to solve. For example, with variables x, y and z, you would need three equations.

Ending1: In the equation x, y + y = y, this equals 80. [substeps] When you like a number in linear equations, multiply that number by the number of variables to get 100. Ending2: If you have four variables, you need four equations. [substeps] If you have fewer equations than the number of variables, you will be able to learn some limiting information about the variables (such as x = 3y and y = 2z), but you cannot get a precise solution. Ending3: [title] Pick a zero-point solution for both variables. [step] The simplest solution to solving this problem is to consider your data. Ending4: [title] Make sure that you understand the solutions of all variables. [step] This can help you to make incremental benchmarks about which variables to break down.

Answer format: ending1/ending2/ending3/ending4