问题
解答题
计算化简. ①23÷(
②2a2b-(-
③(a+1)(a-1)-(a-1)2; ④(x+y+3)(x+y-3). |
答案
①原式=8÷4+1=2+1=3;
②原式=-a3b+2a2b3;
③原式=a2-1-a2+2a-1=2a-2;
④原式=(x+y)2-9=x2+2xy+y2-9.
计算化简. ①23÷(
②2a2b-(-
③(a+1)(a-1)-(a-1)2; ④(x+y+3)(x+y-3). |
①原式=8÷4+1=2+1=3;
②原式=-a3b+2a2b3;
③原式=a2-1-a2+2a-1=2a-2;
④原式=(x+y)2-9=x2+2xy+y2-9.