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Course: Algebra (all content) > Unit 5
Lesson 1: Systems of equations overview- Systems of equations: trolls, tolls (1 of 2)
- Systems of equations: trolls, tolls (2 of 2)
- Systems of equations with elimination: King's cupcakes
- Systems of equations with elimination: potato chips
- Systems of equations with substitution: potato chips
- Systems of equations number of solutions: fruit prices (1 of 2)
- Systems of equations number of solutions: fruit prices (2 of 2)
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Systems of equations with substitution: potato chips
To solve a system of equations using substitution...
1. Isolate one of the variables in one of the equations, e.g. rewrite 2x+y=3 as y=3-2x.
2. You can now express the isolated variable using the other one. *Substitute* that expression into the second equation, e.g. rewrite x+2y=5 as x+2(3-2x)=5.
3. Now you have an equation with one variable! Solve it, and use what you got to find the other variable.
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