Online Algebra Calculator
Many of users do not use powerful Maxima computer algebra system for systematic work, but for ad hoc algebraic calculations – equations, functions, matrixes, etc. only. To do this job, it is not useful to download the whole application from a web site.
-- Option variable: ratdenomdivide Default value: true
When ratdenomdivide is true, ratexpand expands a ratio in which the numerator is a sum into a sum of ratios, all having a common denominator. Otherwise, ratexpand collapses a sum of ratios into a single ratio, the numerator of which is the sum of the numerators of each ratio.

Examples:
(%i1) expr: (x^2 + x + 1)/(y^2 + 7);
2
x + x + 1
(%o1) ----------
2
y + 7
(%i2) ratdenomdivide: true$
(%i3) ratexpand (expr);
2
x x 1
(%o3) ------ + ------ + ------
2 2 2
y + 7 y + 7 y + 7
(%i4) ratdenomdivide: false$
(%i5) ratexpand (expr);
2
x + x + 1
(%o5) ----------
2
y + 7
(%i6) expr2: a^2/(b^2 + 3) + b/(b^2 + 3);
2
b a
(%o6) ------ + ------
2 2
b + 3 b + 3
(%i7) ratexpand (expr2);
2
b + a
(%o7) ------
2
b + 3(%o1) true (%i2)