（x+8）（x+1）=﹣12（運用適當的方法）                                ...

問題詳情：

（x+8）（x+1）=﹣12（運用適當的方法）                                              

【回答】

x2+9x+8=﹣12，                                                                                 

∴x2+9x+20=0，                                                                                 

∴（x﹣4）（x﹣5）=0，                                                                        

x=4或x=5                                                                                          

知識點：解一元二次方程

題型：計算題