已知-4x^2-4x+3=0,则3x^2+12x-3

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已知-4x^2-4x+3=0,则3x^2+12x-3已知-4x^2-4x+3=0,则3x^2+12x-3已知-4x^2-4x+3=0,则3x^2+12x-3-4x^2-4x+3=04x^2+4x-3=

已知-4x^2-4x+3=0,则3x^2+12x-3
已知-4x^2-4x+3=0,则3x^2+12x-3

已知-4x^2-4x+3=0,则3x^2+12x-3
-4x^2-4x+3=0
4x^2+4x-3=0
(2x+3)(2x-1)=0
解得
x= -3/2 或 x= 1/2
3x^2+12x-3
=3x^2+12x+12-15
=3(x+4)^2-15
当 x= -3/2时
原式= 3 * 25/4 -15 = 15/4 =3.75
当 x= 1/2 时
原式 = 3* 81/4-15= 183/4 =45.75