Question

几道初二分式的计算题,超级急!1.已知 4 A Bx+C-------- = ---+ ------,则A= B= C=

Answer 1

4/x(x^2+4)=A/x+(Bx+C)/(x^2+4)

=(ax^2+4a+bx^2+cx)/x(x^2+4)

=[(a+b)x^2+cx+4a]/x(x^2+4)

所以a+b=0

c=0

4a=4

a=1,b=-1,c=0

a+1-a/(a-1)

=a+1-(a-1+1)/(a-1)

=(a+1)-[1+1/(a-1)]

=a-1/(a-1)

=(a^2-a-1)/(a-1)