1、提分专练 (一)实数的运算与代数式的化简求值|类型1|实数的混合运算1.2019广安计算:(-1)4-|1-3|+6tan30-(3-27)0.2.计算:(-3)2-|3-5|+20+12-2.3.2019遂宁计算:(-1)2019+(-2)-2+(3.14-)0-4cos30+|2-12|.|类型2|整式的化简求值4.2019长沙先化简,再求值:a+3a-1-1a-1a2+4a+4a2-a,其中a=3.5.2019株洲先化简,再求值:a2-a(a-1)2-a+1a,其中a=12.6.2018抚顺先化简,再求值:1-x+3x+1x2+4x+4x+1,其中x=tan45+12-1.【参考答案】1
2、.解:原式=1-(3-1)+633-1=1-3+1+23-1=1+3.2.解:原式=9-(3-5)+25+4=9-3+5+25+4=10+35.3.解:(-1)2019+(-2)-2+(3.14-)0-4cos30+2-12=-1+14+1-432+23-2=-74.4.解:原式=a+2a-1a(a-1)(a+2)2=aa+2,当a=3时,原式=33+2=35.5.解:a2-a(a-1)2-a+1a=a(a-1)(a-1)2-a+1a=aa-1-a+1a=a2-(a-1)(a+1)a(a-1)=a2-a2+1a(a-1)=1a(a-1),当a=12时,原式=112(12-1)=-4.6.解:原式=1-x2+3x+1(x+2)2x+1=(2+x)(2-x)x+1x+1(x+2)2=2-xx+2,x=tan45+12-1=1+2=3,原式=-15.
