\(-3 ⋅ 7 p = -21 p\)

\(7 x ⋅ 4 y = 28 x y\)

\(-3 x ⋅ -4 y = 12 x y\)

\(-7 a ⋅ -9 a = 63 a^{2}\)

\(-2 a ⋅ -3 b ⋅ 5 c = 30 a b c\)

\(p ⋅ -4 q ⋅ -5 p = 20 p^{2} q\)

\(9 a + 8 a = 17 a\)

\(4 x y + 6 x y = 10 x y\)

\(7 a + 3 a + 9 a = 19 a\)

Kan niet korter.

\(0 ⋅ 2 a = 0\)

\(7 x ⋅ 3 x y = 21 x^{2} y\)

\(5 b ⋅ -2 ⋅ -3 a b = 30 a b^{2}\)

\(x + x + x + x + x + x + x = 7 x\)

\(6 a - 8 a = -2 a\)

\(-3 x - 4 x = -7 x\)

\(-3 p q - 2 p q = -5 p q\)

\(0 - 5 x = -5 x\)

Kan niet korter.

\(2 x - 2 x = 0\)

\(2 a + 6 b - 8 a = -6 a + 6 b\)

\(-3 x + 4 y - y = -3 x + 3 y\)

\(-p - 2 q - 3 p + 4 q = -4 p + 2 q\)

\(-8 a - 6 + 2 a - 7 = -6 a - 13\)

\(-6 p + -8 q + 3 p = -3 p - 8 q\)

\(-6 x - -7 x + 8 y = x + 8 y\)

\(5 x + 2 x y + 3 y - 8 x y = 5 x + 3 y - 6 x y\)

\(-9 a b + 4 b - 6 a b - 4 b = -15 a b\)