# Algebra 1 Common Core Student Edition, Grade 8-9

(Marvins-Underground-K-12) #1
``Getting Ready!``

``````Th e diagram shows t h e amount o f money t h at each p layer st ar t s wit h
in a video game. To be f a i r , each p layer should have t he same amount
of money. What amount must be in the chest? How do you know?``````

``````@ Common Core State Standards
A-CED.A.1 Create equations... in one variable and use
them to solve problems. Include equations arising from
lin e a r ... functions. Also A-REI.B.3
MP 1, M P 3 , MP 4, MP 7``````

``Objective T o s o lv e o n e - s te p e q u a t io n s i n o n e v a r ia b le``

Solving One-Step

Equations

``````Fi r st make a plan
f o r how you ar e
going t o solve t his
problem.``````

``````MAtHEMAtlCAL
PRACTICES``````

``Player 1 Player 2``

``````Lesson
Vocabulary
equivalent
equations``````

• A d dition
Property of
Equality

• Subtraction
Property of
Equality

• isolate

• inverse
operations

• M ultiplication
Property of
Equality

• Division Property
of Equality

``````I n th e S o lv e It, y o u m a y h a v e u s e d r e a s o n in g to f i n d th e a m o u n t o f m o n e y i n th e c h e s t.
In this lesson, you w ill learn to solve problem s like the one above by using equations.``````

``````Esse n t i a l U n d e r st a n d i n g Equivalent equations a re e q u a t io n s t h a t h a v e th e
s a m e s o lu t io n ( s ). Y o u c a n f i n d th e s o lu t io n o f a o n e - s te p e q u a t io n u s in g t h e p r o p e r t ie s
o f e q u a lit y a n d in v e r s e o p e r a t io n s to w r it e a s im p le r e q u iv a le n t e q u a t io n.``````

Pr o p er t y Addition and Subtraction Properties of Equality

``````Addition Property of Equality A d d in g t h e s a m e n u m b e r t o e a c h s id e o f a n e q u a t io n
produces an equivalent equation.
Algebra Example
For any real num bers a, b, and c,
if a = b, then a + c = b + c.``````

``````x — 3 = 2
x — 3 + 3 = 2 + 3``````

``````Subtraction Property of Equality S u b t r a c t in g t h e s a m e n u m b e r f r o m e a c h s id e o f a n
equation produces an equivalent equation.
Algebra
For any real num bers a, b, and c,
ifa = b, th e n a — c = b — c.``````

``````Example
X+ 3 = 2
x + 3 — 3 = 2``````

I

``PowerAlgebra.com ^ | Lesson 2-1 Solving One-Step Equations 81``