0.5x²-1/5x³,其中x=12/13

问题描述:

0.5x²-1/5x³,其中x=12/13

0.5x²-1/5x³
=1/10x²(5-2x)
=1/10×144/169×(5-24/13)
=1/5×72/169×41/13
=2952/10985