解:(2a+b)(b﹣2a)﹣(a﹣3b)2
=b2﹣4a2﹣a2+6ab﹣9b2
=﹣5a2+6ab﹣8b2,
当a=﹣2,b= 32
设m、n是空间不同的直线,α、β是空间不同的平面,对于命题:p:m⊥n,m⊥α⇒n∥α,命题q:m⊥α,m∥β⇒α⊥β,下面判断正确的是( )
You had better ____ (not eat) so much fried chicken. ____ (eat) too much ____(make) you unhealthy.
设函数fx=2-x-1,x≤0x12,x>0若fx0>1,则x0的取值范围是( )