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

(Marvins-Underground-K-12) #1
``mu``

Co n cep t Byt e

``Use W ith Lesson 2-1``

Modeling One-Step

Equations

``````© Common Core State Standards
Prepares fo r A-REI.A.1 Explain each step in
solving a simple equation as following from the
equality o f numbers asserted at the previous
step,...``````

``````Unit tiles
J = +1 * = -1``````

``*+ J = 0``

``Variable tiles``

``■ = a variable, such asx``

``MP 7``

``````A lg e b r a tile s c a n h e lp y o u u n d e r s t a n d h o w to s o lv e o n e - s te p e q u a t io n s i n o n e
variable. You can use the algebra tiles shown below to m odel equations. Notice that
th e y e llo w t i l e is p o s it iv e a n d th e r e d t i l e is n e g a tiv e. T o g e th e r, t h e y f o r m a z e ro p a ir,
which represents 0.``````

``````Activity
Model and solve x - 2 = 4.``````

``Equation``

``x = 6``

``Algebra tiles``

``````XI ii gam ■^ ■ _j _j
J J
/
mu J J
2 + 2 = 4 + 2 J J
J J``````

``````■HiJ J
J J
J J``````

``Step``

``Model the equation using tiles.``

``````The green tile represents x. To get the
green tile by itself on one side o f the
equation, add tw o yello w tiles to each
side. Remember, a yellow tile and a red tile
form a zero pair. Remove all zero pairs.``````

``````The green tile equals six yellow tiles.
This represents x = 6. The solution of
x - 2 = 4 is 6.``````

``````Ex e r c i se s
Write the equation modeled by the algebra tiles.``````

``````HHI -J J J J J J J
JJ J HHI J J``````

``````Use algebra tiles to model and solve each equation.
3.x—3 = 2 4.x —4 = 7 5. x + 1 = 5``````

1. 1 + x = - 3 8. 5 + x = - 3 9. x - 4 = — 3

``````6. x + 4 = 7
10. —4 + x = —8``````

80 Co n cep t By t e Modeling One-Step Equations