计算:
(1) 4 - tan 45 ° - ( 1 - 2 ) 0 ;
(2) ab ( 3 a - 2 b ) + 2 a b 2 .
(1)解方程:x2﹣4x+2=0 (2)解不等式组:.
计算: (1)计算: (2)计算:3(x2+2)﹣3(x+1)(x﹣1)
先化简,再求值:,其中x=6.
(1)计算:; (2)计算:.
设m、n是一元二次方程x2+3x-7=0的两个根,则m2+4m+n= ▲.