原式=1.234^2+0.766^2+2×1.234×0.766
=(1.234^2+1.234×0.766)+(0.766^2+1.234×0.766)
=1.234×(1.234+0.766)+0.766×(0.766+1.234)
=(1.234+0.766)×(0.766+1.234)
=4
1.234�0�5+0.766�0�5+2.468×0.766= 1.234�0�5+2×1.234×0.766×0.766�0�5= (1.234+0.766)�0�5= 2�0�5= 4