â 8th Grade Math · Unit 5
Systems of Linear Equations
11 short narrated lessons in 2 chapters, each with pictures, a quiz with a hint and a second try, and an explanation for every answer.
Standards: 8.EE.C.8
What your child will learn
Solving systems
- What Is a System of Equations?Explain that a solution to a system of two equations is a point that makes both true.
- Solving Systems by GraphingSolve a system by graphing both lines and finding where they cross.
- Solving Systems by SubstitutionSolve a system by replacing one variable with an expression from the other equation.
- Solving Systems by EliminationSolve a system by adding or subtracting equations to eliminate a variable.
- How Many Solutions Does a System Have?Tell whether a system has one solution, no solution or infinitely many by comparing slopes and intercepts.
- Solving Systems Review ReviewReview solving systems by graphing, substitution and elimination and counting solutions.
Systems in the real world
- Writing Systems from Word ProblemsWrite a system of two equations from a word problem with two unknowns.
- Comparing Plans and PricesUse a system to find when two plans, like two gym memberships, cost the same.
- Mixture and Total ProblemsSolve problems about totals, like tickets or coins of two kinds, with a system.
- Systems in the Real World Review ReviewReview writing and solving systems for real-world problems.
- Unit 5 Test: Systems of Linear EquationsShow what you learned in the whole unit (Solving systems, Systems in the real world) by answering mixed questions.
Try a question from this unit
From the lesson âWhat Is a System of Equations?â
Which point is a solution of the system y = x + 2 and y = 3x - 2?
Show the answer
(2, 4). For (2, 4), 2 + 2 = 4 and 3(2) - 2 = 4, so both equations are true. The point (1, 3) is tempting because it fits y = x + 2, but 3(1) - 2 is 1, not 3.
Hint kids see after a wrong try: âTest each point in the first equation, then test the survivors in the second one.â
Key words
- system of equations
- solution
- point of intersection
- substitution
- elimination
- parallel lines
- same line
- unknown
- break-even point
- total
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Narrated lessons, pictures and quizzes for every grade from K to 8. Works offline.
