设x、y、x'、y'是自然数,定义(x,y,x',y')=xy+x'y',计算(1,2,3,4),(3,4,1,2),(2,3,4,1),(4,1,2,3),(14,10,14,10)的值.

问题描述:

设x、y、x'、y'是自然数,定义(x,y,x',y')=xy+x'y',计算(1,2,3,4),(3,4,1,2),(2,3,4,1),(4,1,2,3),(14,10,14,10)的值.

(1,2,3,4)=1*2+3*4=14;
(3,4,1,2)=3*4+1*2=14;
(2,3,4,1)=2*3+4*1=10;
(4,1,2,3)=4*1+2*3=10;
(14,10,14,10)=14*10+14*10=280.