1、4a5b4-4a6b3+4a7b2 (a5b4代表a的五次方b的四次方)
2、3(x+4)(x-4)-3(x+8)(x-1)=11
3*（-16）-21X+24=11
X=5/3
3、3x-x[(2x²-4x+1)-2(3x²-1/2x+1)]
=3x-x[ 2x²-4x+1-6x²+x-2]
=3x-x[-4x²-3x-1]
=3x+4x3+3x²+x
=4x^3+3x²+4x
代入x=1/3
解得原式=4/27+1/3+4/3
=49/27