\

From the graph:

The library of congress has 28.7 millions of volumes.

The Boston Public Library has 14.6 millions of volumes.

Let n represent the number of more volumes the library of congress had than

the Boston Public Library.

Write the verbal expression to represent the situation.

Rewrite the equation:

14.6 + n = 28.7 \ \

Subtraction property of equality:  if a = b, then a c = b c.

14.6 + n 14.6 = 28.7 14.6

n = 28.7 14.6                           (Additive inverse property:14.6 14.6 = 0)    

\

 n = 14.1                                 (Subtract: 28.7 14.6 = 14.1)

The library of congress has 14.1 more millions of volumes than the Boston

Public Library.