Algebra 1 Common Core Student Edition, Grade 8-9

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

7. 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