初二上册的数学题,麻烦要有步骤,谢谢!
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解方程

X(9X-5)-(3X+1)(3X-1)=5

9x^2-5x-9x^2+1=5

5x=-4

x=-4/5

(X-1)(X-3)+25=(X+2)(X+4)

x^2-4x+28=x^2+6x+8

10x=20

x=2

1.(-X)³(-Y)²-(-X³Y²)

=-x^3y^2-(-x^3y^2)

=0

2.-9A²B³C²÷(-3AB)²

=.-9A²B³C²÷9A²B²

=-BC^2

化简求值

(2X-Y)(Y+2X)-(2Y+X)(-2Y-X)其中X=1 Y=2

=4x^2-y^2+(2y+x)^2

=4x^2-y^2+4y^2+4xy+x^2

=5x^2+4xy+3y^2 X=1 Y=2

= 5+40+12

=57

(A-2B+C)²=[(A+C)-2B]^2=(A+C)^2-4B(A+C)+4B^2=A^2+2AC+C^2-4AB-4BC+4B^2

3AB-4BC+1=3AB-( 4BC-1 )

X²-A²+4A-4=X²-( A^2-4A+4)=x^2-(A-2)^2=(x-A+2)(x+A-2)

(2/3)²º¹³(-1 - 1/2)的2014次方

=(2/3)²º¹³*(3/2)^2014

=(2/3)²º¹³*(3/2)^2013*(3/2)

=[(2/3)*(3/2)]^2013*(3/2)

=3/2

当X=1 Y=1/5时,当3X(2X+Y)-2X(X-Y)的值

3X(2X+Y)-2X(X-Y)

=6x^2+3xy-2x^2+2xy

=4x^2+5xy

=x(4x+5y) X=1 Y=1/5

=1*(4+1)

=5

已知A+B=6. AB=-27

A²+B²=(A+B)^2-2AB=36-2*(-27)=36+54=90

(A-B)²

=A^2+B^2-2AB

=90-2*(-27)

=90+54

=144

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