Question

(1)ab分之a+b - bc分之bc (2)(x-3)的平方分之3x - 3-x分之x

Answer 1

(1)ab分之a+b - bc分之bc

(a+b)/ab -(b+c)/bc

=[(a+b)c-(b+c)a]/abc

=(ac+bc-ab-ac)/abc

=(bc-ab)/abc

=b(c-a)/abc

=(c-a)/ac

(2)(x-3)的平方分之3x - 3-x分之x

=3x/(x-3)² - x/(3-x)

=3x/(x-3)² + x/(x-3)

=3x/(x-3)² + x(x-3)/(x-3)²

=(3x+x²-3x)/(x-3)²

=x²/(x-3)²