(1).(2-3a^2)(3a^2-2)(2)(1/2x+2)(1/2x+2)+(-3-x)(-x-3)^号代表平方.
(1).(2-3a^2)(3a^2-2)
(2)(1/2x+2)(1/2x+2)+(-3-x)(-x-3)
^号代表平方.
(1)=-(3a^2-2)^2=-9a^4+12a^2-4
(2)=(1/2x+2)^2+(x+3)^2=x^2+6x+2/x+1/(4x^2)+13
(1) (2-3a^2)(3a^2-2) =-(3a^2-2)(3a^2-2)=-(9a^4-4)=4-9a^4
(2) (1/2x+2)(1/2x+2)+(-3-x)(-x-3) =(1/2x+2)^2+(-3-x)^2=(1/4x^2+4+4x)+(9+x^2+6x)=5/4x^2+10x+13
满意不?????
(1).(2-3a^2)(3a^2-2)
=-(3a^2-2)(3a^2-2)=-(3a^2-2)^2
=-9a^4+12a^2-4
(2)(1/2x+2)(1/2x+2)+(-3-x)(-x-3)
= (1/2x+2)^2+(x+3)^2
=(1/4x^2+2x+4)+(9+6x+x^2)
=5/4x^2+8x+13
(1).(2-3a^2)(3a^2-2)
=6a^2-4-9a^4+6a^2
=-9a^4+12a^2-4
(2)(1/2x+2)(1/2x+2)+(-3-x)(-x-3)
=1/4x^2+2x+4+x^2+6x+9
=5/4x^2+8x+13
(1).(2-3a^2)(3a^2-2)
=[-(3a^2-2)](3a^2-2)
=-(3a^2-2)^2
=-(9a^4-12a^2+4)
=-9a^4+12a^2-4
(2)(1/2x+2)(1/2x+2)+(-3-x)(-x-3)
=(1/2x+2)^2+(-3-x)^2
=(1/4x^2+2x+4)+(9+6x+x^2)
=5/4x^2+8x+13
(1).(2-3a^2)(3a^2-2)
=6a^2-9a^3-4+6a^2
=-9a^3+12a^2-4
(2)(1/2x+2)(1/2x+2)+(-3-x)(-x-3)
=1/4x^2+x+4+9-6x+x^2
=5/4x^2-5x+13