Question

3x的平方+（-2分之3x+3分之1y的平方）（2x-3分之2y）其中x=-3分之1，y=3分之2

Answer 1

3x²+﹙﹣3/2x+1/3y²﹚﹙2x-2/3y﹚
=3x²-3x²+xy+2/3xy²-2/9y³
=xy+2/3xy²-2/9y³
=y﹙x+2/3xy-2/9y²﹚
=2/3×[﹣1/3+2/3×﹙﹣1/3﹚×2/3-2/9×﹙2/3﹚²]
=2/3×[﹣1/3-2/27-8/81]
=2/3×﹙﹣41/81﹚
=﹣82/243