-4分之1x的4次方+9y²,x²-(x-y),已知4m+3n=90,2m－3n＝10,求(m＋2n)²－(3m－n)²的值,-4分之1x²y²+0.09,4x²-(x-y),101²-99²,

-4分之1x的4次方+9y²,x²-(x-y),已知4m+3n=90,2m－3n＝10,求(m＋2n)²－(3m－n)²的值,-4分之1x²y²+0.09,4x²-(x-y),101²-99²,
-4分之1x的4次方+9y²,x²-(x-y),已知4m+3n=90,2m－3n＝10,
求(m＋2n)²－(3m－n)²的值,-4分之1x²y²+0.09,4x²-(x-y),101²-99²,

-4分之1x的4次方+9y²,x²-(x-y),已知4m+3n=90,2m－3n＝10,求(m＋2n)²－(3m－n)²的值,-4分之1x²y²+0.09,4x²-(x-y),101²-99²,
-1/4x^4+9y²
=-(x/2+3y)(x/2-3y)

x²-(x-y)²
=(x+x-y)(x-x+y)
=(2x-y)y

已知4m+n=90,2m－3n＝10,
(m＋2n)²－(3m－n)²
=(m＋2n+3m－n)(m＋2n-3m+n)
=(4m+n)(-2m+3n)
=90×(-10)
=-900

-1/4x²y²+0.09
=-(x/2+0.3)(x/2-0.3),


x²-(x-y)²
=(x+x-y)(x-x+y)
=(2x-y)y

101²-99²
=(101+99)(101-99)
=200×2
400