Algebra 1 Common Core Student Edition, Grade 8-9

© sj Got It? 4. The table shows th e n u m b e r of gallons of w a te ry

in a ta n k after x hours. The relationship is linear.

W hat is an eq u a tio n in point-slope form th at

m odels th e data? W hat does th e slope represent?

, R e a s o n i n g Write th e eq u a tio n from p a rt (a)

in slope-intercept form. W hat does the

y-intercept represent?

Volume of W ater in Tank

4570

7070

10,820

Lesso n Ch eck

Do you know HOW?

1. W hat are th e slope an d one p o in t on th e g raph of
   y-12 = § (x + 7 )?


2. W hat is an equ atio n of th e line th at passes through
   the p oint (3, - 8 ) an d has slope - 2?


3. W hat is the graph of th e equation y - 4 = 3(x + 2)?


4. W hat is an equation of th e line th at passes through
   the points ( —1, - 2 ) an d (2,4)?

MATHEMATICAL

Do you UNDERSTAND? ^PRACTICES

5. Vocabulary W hat features of th e g raph of the
   eq u a tio n y - y x = m {x - Xj) can you identify?

6. R e a s o n i n g Is y - 4 = 3(x + 1) an equ atio n of a line

through (-2 ,1 )? Explain.

7. Reasoning Can any equation in point-slope form
   also b e w ritten in slope-intercept form? Give an
   exam ple to explain.

Pr act i ce an d Pr o b l em - So l v i n g Ex er ci ses MATHEMATICALPRACTICES

Practice Write an equation in point-slope form of the line that passes through the given

point and with the given slope m.

8. (3, - 4 ) ; m = 6


9. ( —2, —7); m =


10. (4,2); m :


11. (4,0);m

Graph each equation.

12. y + 3 = 2(x — 1)


13. y + 5 = —(x + 2)

Write an equation in point-slope form for each line.

17.

13. y - 1 = —3(x + 2 )


14. y — 2 = l(x — 3)

y

J->

(^11)
X
— 0
4^ See Problem 1.
See Problem 2.
See Problem 3.
318 Chapters Linear Funct ions