现规定一种新的运算"×",满足a×b=ab+a-b,例如:2※3=2×3+2-3=5
问题描述:
现规定一种新的运算"×",满足a×b=ab+a-b,例如:2※3=2×3+2-3=5
(1)请分别计算:(﹣2)※(﹣3),(﹣5)※0,(﹣2)※2分之1,(﹣4)※(﹣5)※(﹣6)
(2)想一想,这种运算有没有有交换律?说说你的理由
答
(-1)*(-3)
=(-1)x(-3)+(-1)-(-3)
=3-1+3
=5
(-5)*0
=(-5)x0+(-5)-0
=0-5
=-5
(-2)*1/2
=(-2)x1/2+(-2)-1/2
=-1-2-1/2
=-7/2
(-4)*(-5)*(-6)
=[(-4)x(-5)+(-4)-(-5)]*(-6)
=(20-4+5)*(-6)
=21x(-6)+21-(-6)
=-126+21+6
=-99