分析:(1)先化簡(jiǎn),再分類計(jì)算;
(2)先同類項(xiàng)歸類,再合并;
(3)先算乘方和絕對(duì)值,再算乘法,最后算減法;
(4)利用解一元一次方程的步驟解方程檢驗(yàn)即可;
(5)先去括號(hào),再合并同類項(xiàng),最后代入求值即可.
解答:解:(1)(-17)+(-13)-18
=-17-13-18
=-48;
(2)8a-a
3+a
2+4a
3-a
2-7a-6
=-a
3+4a
3-a
2+a
2-7a+8a-6
=3a
3+a-6;
(3)(-2)
3×|-3|-(-16.5)
=-8×3+16.5
=-24+16.5
=7.5;
(4)
x+1=3 x=2
x=4;
檢驗(yàn):把x=4代入原方程,
左邊=
×4+1=3,
右邊=3,
左邊=右邊,
所以x=4是原方程的解;
(5)
2x3+4x-x2-(x+3x2-2x3)=2x
3+4x-
x
2-x-3x
2+2x
3=4x
3-
x
2+3x;
當(dāng)x=-3時(shí),
原式=4×(-3)
3-
×(-3)
2+3×(-3)
=4×(-27)-
×9-9
=-108-30-9
=-147.
點(diǎn)評(píng):此題綜合考查有理數(shù)的混合運(yùn)算,整式的加減運(yùn)算,解方程,以及代數(shù)式求值的問(wèn)題.