若f(x)=x^5-4x^4+ax^3十bx一8,分别被x一1知x一2整除,求a和b的值

被x一1知x一2整除,故,f(x) = 0.
x=1,f(x)=x^5-4x^4+ax^3十bx一8=1-4+a+b-8=a+b-11=0,
x=2,f(x)=x^5-4x^4+ax^3十bx一8=32-64+8a+2b-8=8a+2b-40=0,
2a+2b=22,
6a=18,
a=3,
b=8.