2.1-3 Quiz Flashcards
System of Equations
Two or more linear equations
System of Equations Methods to Solve
1) Graph - y=mx+b
2) Substitution - one variable is isolated
3) Elimination - ax+by=c
One Solution
Crosses at one point - (x, y)
No Solution
Parallel lines - # not equal #
Infinitely Many Solutions
Same line - # = #
Algebraic Ways to Solve Systems of Equations
Substitution and elimination
Steps to Solve by Substitution
1) Solve one equation for x or y - isolate a variable
2) Substitute the resulting equation from step 1 into the other equation for that variable
3) Solve for the remaining variable
4) Substitute your answer from step 3 into either original equation to find the other variable
Steps to Solve by Elimination
1) Line up the equations
2) Multiply one or both equations by a number to result in a variable with the same coefficient
3) Add or subtract the equations to eliminate the variable
4) Solve for the remaining variable
5) Substitute your answer from step 4 into either original equation to find the other variable
Steps to Solve Systems of Equations Applications
1) Define your variable - what you are solving for
2) Set up two equations using the information given
3) Solve the system using your method of choice
Steps to Solve Systems with Three Variables
1) Choose two equations in which you can easily eliminate a variable - equation A
2) Eliminate the same variable from a combination of the equation you didn’t use and one of the ones you did - equation B
3) Put equation A and B together and solve that system to find two of your variables
4) Substitute your answers from step 3 into either original equation to find the remaining variable
Systems with Three Variables Solution
Ordered triple - (x, y, z)