f（x）=5x^5+2x^4+3.5x^3-2.6x^2+1.7x-0.8,用秦九韶法计算多项式当x=5时

f（x）=5x^5+2x^4+3.5x^3-2.6x^2+1.7x-0.8
=(5x^4+2x^3+3.5x^2-2.6x+1.7)x-0.8
=[(5x^3+2x^2+3.5x-2.6)x+1.7]x-0.8
={[(5x^2+2x+3.5)x-2.6]x+1.7}x-0.8
=【{[(5x+2)x+3.5]x-2.6}x+1.7】x-0.8
27
27x5+3.5=138.5
138.5-2.6=135.9
135.9x5+1.7=
不算了我

次数---------系数
5-------------5
4------------5*5+2=27
3------------27*5+3.5=138.5
2----------138.5*5-2.6=689.9
1------------689.9*5+1.7=3451.2
0--------- -0.8
所以f（x）=5*5^5+27*5^4+138.5*5^3+689.9*5^2+3451.2*5-0.8=?