Collecting like terms
a + 2a +3a -4a
2a
5c (3+a)
15c +5ac
4 x 3g
12g
8f/2
4f
2a -3a +6a -12a
-7a
8(3 +4a)
24 + 32a
2 x 4w x 3y
24wy
12h/14h
6/7
3a + 6b - 3b - 3a
3b
15a (2a -3b)
30a^2 -45ab
-5t x 4dh
-20dht
21ab/28b
3a/4
5a +6c -4b + b + b -3a +9c
2a +15c -2b
4(d+7) - 3(d+2)
d + 22
7pq x 3p x 2q
42p^2q^2
28def/18d
14ef/9
3a^2 + 2ab + 5a^2 - 5b
8a^2 + 2ab - 5b
(a+3)(a+4)
a^2 + 7a + 12
5m x n x 6nt x -t
-30mn^2t^2
25p^12 x 4q^7/15p^2 x 8q^2
5p^10q^5/6
12y + 16y^2
4y(3 + 4y)