(1)-2÷(-)×(-4.5)
(2)
(3)
(4)
(5)1÷(-3)×(-)
(6)
(7)-22×{}
(8)3a+(-8a+2)-(3a-4)
(9)(x2+2xy+y2)-(x2-xy+y2)
(10)9a2-[7a2-2a-2(a2-3a)]-3.
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解:( )-2÷(-)×(-4.5)
=-2×(-)×(-)
=-4;
(2)
=-24×-(-24)×+(-24)×
=-18+20-14
=-12;
(3)
=2-4×2×
=2-1
=1;
(4)
=(-+-)×12
=-×12+×12-×12
=-10+8-9
=-11;
(5)1÷(-3)×(-)
=1×(-)×(-)
=;
(6)
=9-(-)×-6÷
=9-(-)-6×
=9+-
=-;
(7)-22×{}
=-4×{[×(-)+(-)]×(-3)}
=-4×{[(-)+(-)]×(-3)}
=-4×{-×(-3)}
=-4×
=-;
(8)3a+(-8a+2)-(3a-4)
=3a-8a+2-3a+4
=-8a+6;
(9)(x2+2xy+y2)-(x2-xy+y2)
=x2+2xy+y2-x2+xy-y2
=3ay;
(10)9a2-[7a2-2a-2(a2-3a)]-3
=9a2-[7a2-2a-2a2+6a]-3
=9a2-[5a2+4a]-3
=9a2-5a2-4a-3
=4a2-4a-3.
解析分析:(1)先把假分数和小数化为带分数,再按照从左到右的顺序进行计算即可;(2)先用-24同括号中的每一项分别相乘,再把所得结果相加减即可;(3)去绝对值符号,同时把除法变成乘法,再算乘法,最后算减法;(4)把除法变成乘法,再根据乘法的分配律展开,最后合并即可;(5)把除法变成乘法,再根据乘法的法则计算即可;(6)先算乘方,再算乘除,最后算加减;(7)先算乘方和中括号内的除法,再算括号内加法,把除法把乘法,再按乘法法则进行计算即可;(8)先去括号,再合并同类项即可;(9)先去括号,再合并同类项即可;(10)先去小括号,再去中括号,最后合并同类项即可.
点评:本题考查了有理数的混合运算和整式的混合运算,主要考查学生的化简和计算能力.