Problem : 
Are the following statements true sometimes, always, or never for a, b, c, d, k, l > 0?
a)  (a + b)2 = a2 + b2
b)  ca2 + da2 = (c + d )a2
c)  akal = ak+l
d)  akal = akl
e)  (ak)l = akl
f)  a-2 < 1
a)  Never.
b)  Always.
c)  Always.
d)  Sometimes (
k = l = 2, for example).
e)  Always.
f)  Sometimes.
 
Problem : 
Write 256 and 1252 as quantities with a common base.
256 = 512 and 
1252 = 56.