# Week 15 – Math 10

We learned more about graphing and linear equation. W learned about different ways to find solutions to equations. They are Inspection, Substitution, and Elimination.

Inspection is only used when a system is very easy and understood. It is basically just eyeballing the question and guessing what the solution is. You can test your solution by plugging the numbers in the appropriate spots (x and y).

Substitution is another method to find solutions, but it uses algebra. You can choose one of the equations, and then choose on of the variables to isolate. Then you plug it into the correct spot on the other equation. You then use algebra to solve the equation, and then use the answer to plug in to find the other variable.

ex. Elimination is used when there are no coefficients of 1. You start by adding the two equations together (you can subtract but it doesn’t work as well). You want to make a zero pair by making either the x or y cancel the other out. If they don’t do this from the start, you can multiply one of the equations or both of them to get one, and then do your adding. Once you have the answer to one variable, you plug it into the equations and find the other.

ex. 