For all numbers B and D,the operation ＃is defined by b#d=(b-2)(d+1).If (-2)#x=12,then what's the value of x
问题描述：
For all numbers B and D,the operation ＃is defined by b#d=(b-2)(d+1).If (-2)#x=12,then what's the value of x
and why please give your formula and explain.
答
就是除了加减乘除,假设现在有一个新的符号#.
#的算法就是b#d=(b-2)(d+1).
所以(-2)#x=（-2-2）（x+1）=12 所以x=-4