Algebra 1 Common Core Student Edition, Grade 8-9

Concept Byte

Use W ith Lesson 1 -8

Using Tables t o

So l v e Eq u a t i o n s

Common Core State Standards

Prepares fo r A-REI.A.1 Explain each step in solving

a simple equation as following from the equality of

numbers asserted at the previous ste p ,...

MP 5

Y o u c a n s o lv e e q u a t io n s b y m a k in g a t a b le u s in g a g r a p h in g c a lc u la t o r.

Actiyfty

A raft floats downriver at 9 m i/h. The distance y the raft travels can be modeled by

the equation y = 9x, where jc is the number of hours. Make a table on a graphing

calculator to find how long it takes the raft to travel 153 mi.

Stepl Enter the equation y = 9x in to a g ra p h in g c a lc u la to r.

• P re ss T h e c u r s o r a p p e a r s n e x t t o Y j.


• Press 9 to e n te r y = 9x.
  Step 2 A c c e s s t h e t a b le s e tu p fe a tu r e.


• Press


• T b lS ta rt represents th e s ta rtin g va lu e in th e table. E n te r 1 fo r T b lS ta rt.


• A T b l represents th e change in th e va lu e o f x as y o u g o f r o m r o w t o r o w.
  Enter 1 for ATbl.

Step 3 D is p la y th e ta b le a n d fin d th e s o lu tio n.

• P ress fe'llH'aa. U s e " V t o s c r o ll t h r o u g h t h e t a b le u n t i l y o u f i n d th e
  x-value for w hich y = 153. This x-value is 17. I t ta k e s t h e r a f t 17 h to
  tra ve l 153 mi.

MATHEMAIICAL

PRACTICES

TABLE SETUP

TblStart = 1

ATbl = 1

In d p n t : EJ

Depend:

X Yi I

1112 9 9 108

13 117

(^1415126135)
j 16 144
I 17 153
|V = 1 5 3
Ex e r c i se s
Solve each problem by making a table on a graphing calculator.

1. A t o w n p la c e s 5 6 0 1 o f w a s te i n a l a n d f i l l e a c h m o n t h. T h e a m o u n t y o f w a s t e i n
   th e la n d fill can be m o d e le d b y th e e q u a tio n y = 560x, w h e re x is t h e n u m b e r
   o f m o n t h s. H o w m a n y m o n t h s w i l l i t ta k e t o a c c u m u la t e 1 1 ,2 0 0 1 o f w a ste in th e
   la n d fill?


2. A c o u p o n g iv e s $ 1 5 o f f a c u s t o m e r ’s p u r c h a s e. T h e t o t a l a m o u n t y o f t h e
   custom er's purchase can be m odeled by y = x — 15, w h e r e x is th e a m o u n t o f th e
   p u r c h a s e b e fo r e t h e c o u p o n is u s e d. A c u s t o m e r u s in g t h e c o u p o n p a y s $ 1 7 f o r a
   shirt. W hat was the original price of the shirt?

c

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