Question

要初二数学计算题！！越多越好！！

不要网址的，要现题。
要例如：2－X÷(X－1) ÷『X＋1－3÷(X－1)』或X平方＋9Y平方－8X＋6Y=0求1/X－1/Y的值。这种题的

Answer 1

(x^3-1/x^3+2x^2+2x+1)+(x^3+1/x^3-2x^2+2x-1)-2(x^2+1/x^2-1)
解(x^3-1)/(x^3+2x^2+2x+1)+(x^3+1)/(x^3-2x^2+2x-1)-[2(x^2+1)]/(x^2-1)
=(x^3-1)/[x^3+1+2x(x+1)]+(x^3+1)/[x^3-1-2x(x-1)]-[2(x^2+1)]/(x^2-1)
=(x^3-1)/[(x+1)(x^2+1+x)+2x(x+1)]+(x^3+1)/[(x-1)(x^2+1-x)-2x(x-1)]
-[2(x^2+1)]/(x^2-1)
=(x^3-1)/(x+1)[(x^2+1-x)+2x]+(x^3+1)/(x-1)[(x^2+1+x)-2x]
-[2(x^2+1)]/(x^2-1)
=(x^3-1)/[(x+1)(x^2+1+x)]+(x^3+1)/[(x-1)(x^2+1-x)]
-[2(x^2+1)]/(x^2-1)
=[(x-1)(x^2+1+x)]/[(x+1)(x^2+1+x)]+[(x+1)(x^2+1-x)]/[(x-1)(x^2+1-x)]
-[2(x^2+1)]/(x^2-1)
=(x-1)/(x+1)+(x+1)/(x-1)
-[2(x^2+1)]/(x^2-1)
=[(x-1)^2+(x+1)^2-2(x^2+1)]/(x^2-1)
=[(x^2-2x+1)+(x^2+2x+1)-2x^2-2)]/(x^2-1)
=[(-2x+1)+(2x+1)-2]/(x^2-1)
=(1+1-2)/(x^2-1)

x^4+16y^28x^2y 二1/2x^2+2xy+2y^2
解x^4+16y^2+8x^2y
=(x^2)^2+2*x^2*(4y)+(4y)^2
=(x+4y)^2

1/2x^2+2xy+2y^2
=1/2(x^2+4xy+4y^2)
=1/2(x+2y)^2

a/(根号ab+b)+b/(根号ab-a)-(a+b)/根号ab
解a/(根号ab+b)+b/(根号ab-a)-(a+b)/根号ab
=a/√b(√a+√b)+b/√a(√b-√a)-a/√ab-b/√ab
=a/√b(√a+√b)+b/√a(√b-√a)
-√a/√b-√b/√a
=a/√b(√a+√b)-√a/√b
+b/√a(√b-√a)-√b/√a
=√a/√b[(√a-√a-√b)/(√a+√b)]
+√b/√a[(√b-√b+√a)/(√b-√a)]
=√a/√b[(-√b)/(√a+√b)]
+√b/√a[√a/(√b-√a)]
=-√a/(√a+√b)+√b/(√b-√a)
=(a+b)/(b-a)

Answer 2

没有，自己去找！！！！！！！！！！！！

Answer 3

如果1-4/a+4/(a^2)=0.求2/a的值。
解：因为1-4/a+4/(a^2)=0， 所以（1-2/a)^2=0,1-2/a=0,所以2/a=1
(“/”分数线）

Answer 4

(x^3-1/x^3+2x^2+2x+1)+(x^3+1/x^3-2x^2+2x-1)-2(x^2+1/x^2-1)
x^4+16y^28x^2y -1/2x^2+2xy+2y^2
1/2x^2+2xy+2y^2
a/(根号ab+b)+b/(根号ab-a)-(a+b)/根号ab