试题分析:(1)先根据平方差公式去括号,再算加减; (2)由①得 ③,再代入②即可消去y求得x,再把求得的x的值代入③即可求得y; (3)先移项,化二次项系数为1,然后方程的两边同加一次项系数一半的平方,再根据完全平方公式分解因式,最后根据直接开平方法解方程即可; (4)先去括号整理为一元二次方程的一般式,再根据公式法解方程即可; (5)根据两个式子的积为0,这两个式子至少有一个为0,解方程即可; (6)先根据十字相乘法因式分解,即可求得方程的解. (1)原式 ; (2)由①得 ③ 把③代入②得 ,解得![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004756-93891.png) 把 代入③得![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004756-20180.png) 所以原方程的解为 ; (3)![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004756-14699.png)
![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004757-38777.png)
![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004757-59787.png)
![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004757-37741.png)
![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004757-20240.png)
![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004757-83208.png)
; (4)![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004754-81784.png)
![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004758-22174.png)
![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004758-44494.png) ∵![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004758-20927.png) ∴ ; (5)
![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004759-17139.png) 解得 , ; (6)![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004754-51688.png)
![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004759-94833.png)
![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004800-93521.png) 解得 ,![](http://img.shitiku.com.cn/uploads/allimg/20190821/20190821004800-76618.png) 点评:实数的运算、解方程的问题是中考必考题,一般难度不大,同学们需特别慎重. |