1.(b²+2a²)(2a²-b²) 2.(4x²-4y²)(x²+y²) 3.—(x-1)(x+1)-3(x+2)(x-2) 4.(5y²+4x²)[4y²+(2x-y)(-2x-y)]

问题描述:

1.(b²+2a²)(2a²-b²) 2.(4x²-4y²)(x²+y²)
3.—(x-1)(x+1)-3(x+2)(x-2) 4.(5y²+4x²)[4y²+(2x-y)(-2x-y)]

1.(b²+2a²)(2a²-b²)
=2a²b²-b四次方+4a四次方-2a²b²
=4a四次方-b四次方
2.(4x²-4y²)(x²+y²)
=4 (x²-y²)(x²+y²)
=4(X四次方+x²y²-x²y²-y四次方)
=4(X四次方-y四次方)
=4X四次方-4y四次方
3—(x-1)(x+1)-3(x+2)(x-2)
=-(X²-1)-3(X²-4)
=-X²+1-3X²+12
=-4X²+13
4. (5y²+4x²)[4y²+(2x-y)(-2x-y)]
=(5y²+4x²)[4y²-(2x-y)(2x+y)]
=(5y²+4x²)[4y²-4x²+y²]
=(5y²+4x²)(5y²-4x²)
=25Y四次方-16X四次方

1.(b2+2a2)(2a2-b2)=1.(2a2+b2)(2-b2)=4a四次方-b四次方
2.(4x2-4y2)(x2+y2)=4 (x2-y2)(x2+y2)=4(X四次方-y四次方)=4X四次方-4y四次方
3—(x-1)(x+1)-3(x+2)(x-2)=-X2+1-3(X2-4)=-4X2+13
4. (5y2+4x2)[4y2+(2x-y)(-2x-y)]=(5y2+4x2)[4y2-(2x-y)(2x+y)]
=(5y2+4x2)[4y2-4x2+y2]=(5y2+4x2)(5y2-4x2)=25Y四次方-16X四次方
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1.(b²+2a²)(2a²-b²)=1.(2a²+b²)(2-b²)=4a四次方-b四次方2.(4x²-4y²)(x²+y²)=4 (x²-y²)(x²+y²)=4(X四次方-y四次方)=4X...