Sections 3.1-3.4 Review

Vocabulary

100

What do we call rise over run?

slope

200

Lines with a slope of 0 are ___________ and lines with an undefined slope are _____________.

horizontal (0); vertical (undefined)

300

The horizontal change.

Run

400

The y-coordinate of the point where a  line crosses the y-axis.

y-intercept

500

Parallel lines have the _______ slope; perpendicular lines have slopes that are ____________ and ___________.

same (parallel); opposites and reciprocals (perp.)

Slope & Solutions

100

(0,1), (2,7)

slope = 3

200

(1,2), (4, 7)

slope = 5/3

300

(-2,3), (7, -4)

slope = -7/9

400

Is (5, -3) a solution to 2x + y = 13?

No (Plug in the x and y-values and you get 7 = 13)

500

Find k so that (-1, 4) is a solution to y = 3x - k

k = -7

Writing Equations

100

Passes through (1,9), slope = 2 (point-slope form)

y - 9 = 2(x - 1)

200

Passes through (-4,-5), slope = 3/4 (slope-intercept form)

y = 3/4x - 2

300

Passes through (3,-6) and (-1,2) (point-slope form)

y + 6 = -2(x - 3)

400

Passes through (4,-4) and (8,-10) (slope-intercept form)

y = -3/2x + 2

Slope Intercept Form

100

y = -5x + 2

m = -5

b = 2

200

3x + y = -4

m = -3

b = -4

300

Graph the line y = 3x - 2

y-intercept = -2, slope of 3 (rise = 3, run = 1)

400

2y - 2x = 8

m = 1

b = 4

500

-3y = 3x + 4

m = -1

b = -4/3

Formulas for Linear Equations

100

Slope equation

y₂ - y₁

______

x₂-x₁

200

Slope intercept form equation

y= mx + b

300

standard form equation

Ax +By = C

400

Point slope form equation

y - y1 = m(x-x1)