Ratio and Proportion

 c d

 a b =

proportion: two ratios that are equal to each other.

cross products of proportions are equal

 (b)(c) = (a)(d)

Review:

23

3w=

Solve for each variable.

10 y

2y 5=1.)

2.)

You must check for solutions that would not work. Any value of "x" that makes the denominator zero is undefined. This is called an extraneous solution.

-3 d

d - 3 2d

=x + 3 4

x5

=3.) 4.)

x + 3x + 5

x - 3 -5

= 2x - 3 4x

x - 1 x

=5.) 6.)

Demonstrate Understanding:

1.) 2.)

3.)

4.)