几道初一下计算题①4(a-b)^2-(2a+b)(-b+2a)②(x+y)^2*(x-y)^2③(2x-3)(-2x-3)④(3x+4y)^2

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几道初一下计算题①4(a-b)^2-(2a+b)(-b+2a)②(x+y)^2*(x-y)^2③(2x-3)(-2x-3)④(3x+4y)^2
几道初一下计算题
①4(a-b)^2-(2a+b)(-b+2a)
②(x+y)^2*(x-y)^2
③(2x-3)(-2x-3)
④(3x+4y)^2

几道初一下计算题①4(a-b)^2-(2a+b)(-b+2a)②(x+y)^2*(x-y)^2③(2x-3)(-2x-3)④(3x+4y)^2
①4(a-b)²-(2a+b)(-b+2a)
=4a²-8ab+4b²-(-2ab+4a²-b²+2ab)
=5b²-8ab
②(x+y)² ×(x-y)²
=(x²+2xy+y²)(x²-2xy+y²)
=x⁴-2x²y²+y⁴
③(2x-3)(-2x-3)
=-(2x-3)(2x+3)
=-[(2x)²-3²]
=9-4x²
④(3x+4y)²
=9x²+24xy+16y²