7a+15b-21
9a2-4b2+5
2.8a-1.4b
1712x-1112
x+4y-7
11x2-17xy-9y2+11
83x-1
79xy-2512x-12y
-6x+9y
-x2+12x-2
13ab+2a+5b
12x+18y-30
x-7
103a-52b+1415c
-2x+27
a+6
-34x+4
-6x+23y
7m3+83
41a24+524
-68a15+10615
18a5-5b
-16a4b3
4abc25
-56x5y7
-m6n72
24x4
-27m7n4
2a4b4c47
a9b11c784
-23m3
-2y2z3x
-8p2q7r83
-28a33b2
-43a3
2ab23c
-24y2x
c29a4b4
2a29b
-5p3q22
2xy2z