在线百科&&计算器

http://www.idomaths.com/gauss_jordan.php

https://oeis.org/

http://www.algebrasolver.totalh.com/

http://math.cowpi.com/systemsolver/

http://www.wolframalpha.com/

http://www.easycalculation.com/matrix/matrix-addition.php

http://www.mathway.com/

http://www.csie.ntnu.edu.tw/~u91029/index.html

http://www.edcc.edu/faculty/paul.bladek/Cmpsc142/default.htm