计算(4x^2/2x-1)-2x-12.(x-2y+3)(x+2y-3) 3.m^4-18m^2+81

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计算(4x^2/2x-1)-2x-12.(x-2y+3)(x+2y-3) 3.m^4-18m^2+81

计算(4x^2/2x-1)-2x-12.(x-2y+3)(x+2y-3) 3.m^4-18m^2+81
计算(4x^2/2x-1)-2x-1
2.(x-2y+3)(x+2y-3) 3.m^4-18m^2+81

计算(4x^2/2x-1)-2x-12.(x-2y+3)(x+2y-3) 3.m^4-18m^2+81
1.
4x²/(2x-1) -2x-1
=[4x²-(2x+1)(2x-1)]/(2x-1)
=(4x²-4x²+1)/(2x-1)
=1/(2x-1)
2.
(x-2y+3)(x+2y-3)
=[x-(2y-3)][x+(2y-3)]
=x²-(2y-3)²
=x²-4y²+12y-9
3.
m^4 -18m²+81
=(m²-9)²
=[(m+3)(m-3)]²
=(m+3)²(m-3)²

(4x^2/2x-1)-2x-1
=(4x^2-1+1)/(2x-1)-2x-1
=(4x^2-1)/(2x-1)+1/(2x-1)-2x-1
=2x+1+1/(2x-1)-2x-1
=1/(2x-1)