定义新运算e为xey=2xy-(x+y),求12e(3e4)

问题描述:

定义新运算e为xey=2xy-(x+y),求12e(3e4)

3e4
= 2*3*4 - (3 + 4)
= 24 - 7
= 17
12e(3e4)
= 12 e 17
= 2*12*17 - (12 + 17)
= 408 - 29
= 379