计算 (30 16:35:50)①（Xm-yn)(Xm+yn)=②(-1/2a+1/3)2(1/2a-1/3b)2③(-2X2+1_数学解答

计算 (30 16:35:50)
①（Xm-yn)(Xm+yn)=
②(-1/2a+1/3)2(1/2a-1/3b)2
③(-2X2+1/2)(-2X2-1/2)

人气：363 ℃　时间：2020-08-24 14:25:40

解答

①（Xm-yn)(Xm+yn)=XM²-YN²
②(-1/2a+1/3)2(1/2a-1/3b)2
如果2是乘可以先提出来
③(-2X2+1/2)(-2X2-1/2)
平方差公式（A-B）（A+B）=A²-B²