Foundations Chapter 3 Review

Intercepts

100

The x-intercept is to the x-axis as the y-intercept is to the _________.

y-axis

200

To find the y-intercept, we substitute a ____ for the x variable.

0

300

Find the x-intercept:

3x + 4y = 30

(10, 0)

400

Find the y-intercept

x - 5y = 25

(0, -5)

500

Find the x-intercept:

y = 3x + 9

(-3, 0)

Slope

100

Definition of slope

rise/run, change in y/change in x

200

Write the equation we use to find the slope.

(y2 - y1)/(x2 - x1)

300

Find the slope between (3, 8) and (7, 14). Write in simplest form.

3/2

400

Find the slope of the following line and simplify:

(-4, 6) and (8, 6)

0

500

create 2 points that have an undefined slope

(x, any y) (same x, any y)

Direct Variation

100

How do you find the constant of variation?

k = y/x

200

Equation of direct variation

y = kx

300

If y = 42 and x = 3, write a direct variation equation

y = 14x

400

If y = 18 and x = 2, find x if y = 54

x = 6

500

If y = 4 and x = 28, find y if x = 15

15/7 or 2.1

Miscellaneous

100

A line that goes down and to the right has a __________________ slope.

negative

200

What are the 4 different types of slope?

positive, negative, zero, and undefined

300

Write an equation that is nonlinear.

Any equation where a variable has an exponent that is not 0 or 1

400

If y = 32, what does x need to be to make the constant of variation equal 2?

x = 16

500

Find the x and y intercepts:

4x - 6y = 10

x-int: (5/2, 0) y-int: (0, -5/3)