Algebra 1 Common Core Student Edition, Grade 8-9

£ Got It? 4. W hat is the slope of the line th rough th e given points?

a. ( 4 , - 3 ) , (4, 2) b. (-1 ,-3 ), (5,-3)

The following sum m arizes w hat you have learn ed ab o u t slope.

C o n c e p t S u m m a r y Slopes o f Lines

A lin e w ith p o s itiv e s lo p e

slants upw ard from left

to right.

A line w ith negative slope

slants dow nw ard from left

to right.

A line w ith a slope of 0

is horizontal.

y

X

0

A line w ith an u ndefined

slope is vertical.

y

X

0

Lesso n Ch eck

Do you k n o w HO W?

1. Is th e rate of change in cost co n stan t w ith respect to
   the n u m b e r of pencils bought? Explain.

Cost of Pencils

Number of Pencils (^14) ...._____ 7 12
Cost ($) 0.25
1
1.75
E

2. W hat is th e slope of th e line?

1 y

2 0 X

1

3. W hat is the slope of the line through ( - 1 , 2 )
   an d (2, - 3 )?

MATHEMATICAL

Do you UNDERSTAND? \{2jJ PRACTICES

4. Vocabulary W hat characteristic of a graph represents
   th e rate of change? Explain.


5. O pen-Ended Give an exam ple of a real-world
   situation th a t you can m odel with a horizontal line.
   W hat is th e rate of change for the situation? Explain.

6. C o m p a r e a n d C o n t r a s t How does finding a line's

slope by counting u nits of vertical an d horizontal

change on a g raph com pare w ith finding it using the

slope formula?

7. Error Analysis A s tu d e n t
   calculated the slope of the
   line at the right to be 2.
   Explain th e m istake. W hat is
   th e correct slope?

0

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