This one's a little harder:
 

Solve       (2/5)x = 4

There are two ways to attack this guy:

WAY 1:

Do a little at a time...  First, undo the 5:

5 * (2/5)x = 4 * 5  which gives   2x = 20

Now, undo the 2:

2x / 2 = 20 / 2  which gives x = 10

WAY 2:

Use your knowledge of fractions and multiplicative inverses:

(5/2) * (2/5)x = 4 * (5/2)   which gives   (10/10)x = (4/1) * (5/2)  which gives   x = 20/2  which gives  x = 10


YOUR TURN:

Solve         (7/3)x = 14          *Both ways... and check it!

Here's the second thing we can do:

We can multiply or divide both sides of an equation by a number!