x^2-4
r-59
a+b
a^2+6a+9
x^2+10x+25
5x^2-6y^3+1/3 a^2
x^2-5x+6
m
-8m^2n^5
ab^2
x-y
5yz
x^3+x^2-x
-6b
x^2+2/5 x +1/25
6xy^4
a^3+a^2-ab^3
10x^2
3a
x^2y^3
a+b+c
-11xy
9x^3+1
3.5m^2n
