计算: ( 2 − 1 ) 0 − 12 × sin 60 ° + ( − 2 ) 2 .
.(本题8分)计算:
(本题15分)计算:(1)(2)(3)
计算:
解方程:2x2-6x+1=0.
计算: (1) 6-1+(-6)+13 (2)