Answers

2014-06-19T19:27:23+08:00
Pattern:
1.the sum of the squares of the first,second,and last terms
2.twice the product of the first and second terms
3.twice the product of the first and last terms.
4.twice the product of the second and last terms


Answers:
1.r²+t²+n²-2rt+2nr-2nt
2.e²+4a²+q²+4e²a²+2eq+4aq

Repeat the pattern to answer the others.
12 3 12