AbeNeedsAnswers wrote:What is the value of integer n?
(1) n(n+1) = 6
(2) 2^(2n) = 16
$$? = n\,\,\,\,\left( {n\,\,{\mathop{\rm int}} } \right)$$
$$\left( 1 \right)\,\,\,n\left( {n + 1} \right)\, = 6\,\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\,\,\,\left\{ \matrix{
\,n = 2\,\,\,\,\,\,\,\left[ {\,2 \cdot 3 = 6\,} \right] \hfill \cr
\,\,\,{\rm{or}} \hfill \cr
n = - 3\,\,\,\,\,\left[ {\,\left( { - 3} \right)\left( { - 2} \right) = 6\,} \right] \hfill \cr} \right.\,\,\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\,{\rm{INSUFF}}.$$
$$\left( 2 \right)\,\,{2^{2n}} = 16\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\,2n\,\,{\rm{unique}}\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\,n\,\,{\rm{unique}}\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\,{\rm{SUFF}}.$$
This solution follows the notations and rationale taught in the GMATH method.
Regards,
Fabio.
