Question

求下列各式的值:3x平方+(-3/2x+1/3y平方)(2x-2/3y)其中x=-1/3,y=2/3

Answer 1

3X^2+(-3/2X+1/3Y^2)(2X-2/3Y)，
=3X^2-3X^2+xy+2/3xY^2-2/9Y^3
=xy+2/3xY^2-2/9Y^3
=-1/3*2/3-2/3*1/3*4/9-2/9*8/27
=-94/243
自己写的哈，不懂就问哦

Answer 2

3x²+(-3/2x+1/3y²)(2x-2/3y)
=3x²-3x²+xy+2/3xy²-2/9y³
=xy+2/3xy²-2/9y³
=-1/3×2/3+2/3×（-1/3）×（2/3）²-2/9×（2/3)³
=-2/9-4/27-16/81
=-46/81