求填空题和选择题答案
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第1题x不等于-2,-3,-4。第二题sa/[v(v+a)]。第3题a=7.第4题3/5.二选择题:第1题无答案(a^3+3)/(a^2-1) - (a+1)/(a-1) +1
=[(a^3+3)-(a+1)^2+(a^2-1)]/(a^2-1)
=[a^3+3-a^2-2a-1+a^2-1]/(a^2-1)
=(a^3-2a+1)/(a^2-1)
=(a^3-a-a+1)/(a^2-1)
=[a(a^2-1)-(a-1)]/(a^2-1)
=[(a^2+a-1)(a-1)]/(a^2-1)
=(a^2+a-1)/(a+1)。第2题-2即选D。第3题X^2+X=2;所以2-1/2=3/2;即选A;
=[(a^3+3)-(a+1)^2+(a^2-1)]/(a^2-1)
=[a^3+3-a^2-2a-1+a^2-1]/(a^2-1)
=(a^3-2a+1)/(a^2-1)
=(a^3-a-a+1)/(a^2-1)
=[a(a^2-1)-(a-1)]/(a^2-1)
=[(a^2+a-1)(a-1)]/(a^2-1)
=(a^2+a-1)/(a+1)。第2题-2即选D。第3题X^2+X=2;所以2-1/2=3/2;即选A;
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1.
x≠-2且x≠-3
2.
sa/[v(v+a)]
3.
a=7
4.
2/5
二、
1.题目有问题,无答案
(a^3+3)/(a^2-1) - (a+1)/(a-1) +1
=[(a^3+3)-(a+1)^2+(a^2-1)]/(a^2-1)
=[a^3+3-a^2-2a-1+a^2-1]/(a^2-1)
=(a^3-2a+1)/(a^2-1)
=(a^3-a-a+1)/(a^2-1)
=[a(a^2-1)-(a-1)]/(a^2-1)
=[(a^2+a-1)(a-1)]/(a^2-1)
=(a^2+a-1)/(a+1)
2.
1/a-1/b=-2
x≠-2且x≠-3
2.
sa/[v(v+a)]
3.
a=7
4.
2/5
二、
1.题目有问题,无答案
(a^3+3)/(a^2-1) - (a+1)/(a-1) +1
=[(a^3+3)-(a+1)^2+(a^2-1)]/(a^2-1)
=[a^3+3-a^2-2a-1+a^2-1]/(a^2-1)
=(a^3-2a+1)/(a^2-1)
=(a^3-a-a+1)/(a^2-1)
=[a(a^2-1)-(a-1)]/(a^2-1)
=[(a^2+a-1)(a-1)]/(a^2-1)
=(a^2+a-1)/(a+1)
2.
1/a-1/b=-2
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