NAME:___________________________ Math_______,Period____________Mr.Rogove Date:__________

G8M4L25:SolvingSystemsofEquationsbyElimination1

Learning Objective:Wewillsolvesystemsofequationsbyelimination.(G8M4L25) Activating Prior Knowledge: Wecanadd.

2+ 5 =6+ 9 =

−3+ 11 =3+ 2 =

Concept Development: Youcansolvesystemsofequationsbyeliminationbyaddingequationstogethertoeliminateavariable.Example:6! − 5! = 212! + 5! = −5

STRATEGY:WhentouseEliminationMethod1.Whenthetwocoefficientsofoneofthevariablesareopposites.2.Whenyoucanmultiplyoneequationbyanintegernumbertocreateasystemwheretwocoefficientsofoneofthevariablesareopposites.

NAME:___________________________ Math_______,Period____________Mr.Rogove Date:__________

G8M4L25:SolvingSystemsofEquationsbyElimination2

Guided Practice: StepsforSolvingEquationsUsingElimination1.Multiplyoneentireequationbyanintegertocreateoppositecoefficientsforoneofthevariables(ifnecessary).2.Addanentireequationinordertoeliminateonevariable.3.Solveforyourremainingvariable.4.Substituteyouranswerintooneoftheoriginalequationsandsolveforthevariableyoueliminatedoriginally.5.Checkyourworkbysubstitutingyouranswersintotheoriginalequations.

2! + ! = 143! − ! = 4

2! + 3! = 11−2! + 9! = 4

2! − 3! = 212! − ! = 13

5! + 18! = −272! + 18! = −9

NAME:___________________________ Math_______,Period____________Mr.Rogove Date:__________

G8M4L25:SolvingSystemsofEquationsbyElimination3

12! − ! = 266! − 3! = −36

3! − 10! = −302! + 20! = 10

2! + 5! = −10−5! + 4! = 4

7! − 4! = 136! + 3! = 11

NAME:___________________________ Math_______,Period____________Mr.Rogove Date:__________

G8M4L25:SolvingSystemsofEquationsbyElimination4

Independent Practice:

7! + 4! = 136! + 3! = 11

3! − ! = 2110! − 3! = 11

2! + ! = 8! + ! = 10

8! − 5! = 103! + 5! = 12

NAME:___________________________ Math_______,Period____________Mr.Rogove Date:__________

G8M4L25:SolvingSystemsofEquationsbyElimination5

Closure: Choosethemostefficientmethodofsolvingeachsystem:SubstitutionorEliminationandbereadytoexplainyourdecision.NOneedtosolveeachsystem!A. −3! + ! = 13

2! − 3! = 16

SubstitutionorElimination?

B. ! = 4! + 12! = −5! + 81

SubstitutionorElimination?

C. 16! + 13! = 134−4! − 12! = 2

SubstitutionorElimination?

Teacher Notes: Mapstolesson28fromModule4.HWcouldbehandout(orKhan).