① - 2 x ² - 6 x
= - 2(x ² + 3 x)
= - 2(x ² + 3 x + (3 / 2)² ) + 2 × (3 / 2)²
= - 2 (x + 3 / 2)² + 2 × 9 / 4
= - 2(x + 3 / 2)² + 9 / 2
② 6 x + x ²
= (x ² + 6 x + 3 ² )- 3 ²
= (x + 3)² - 9
配方:配成 a ² ± 2 a b + b ² = (a ± b)²
猜你喜欢
- 1()Mr black works in a school.He is a_______.A.policeman B.teacher C.dentist
- 2哪位高人能帮助小妹解答几道高一的数学题?急急急
- 3将一定量硝酸钾的不饱和溶液变成饱和溶液,溶液的质量会如何变化?
- 4古诗:《书湖阴先生壁》的意思是什么?
- 5visit relax stay camp get hike send ride leave forget finish这些单词怎么变成现在分词?
- 6_he said at the meeting astonished everyboby persent.应填什么引导词
- 7小学英语人称代词题
- 8More and more people love taking walks after m____ in the evening
- 9a是不等于b的任何实数,关于x的方程(a-b)x的平方+(c-d)x+c-a=0总有一个根等于?
- 10长波辐射与短波辐射的热量有什么不同?