Răspuns:
a)
[tex]12a + 5a - 7a = 10a[/tex]
b)
[tex]4a - 7a + 3b - b = - 3a + 2b[/tex]
c)
[tex]11ab + 22ab - 10ab - 3ab = 20ab[/tex]
d)
[tex]7x + 3 {x}^{2} - 12x + 20x + 3x - 3 {x }^{2} = \\ 7x - 12x + 20x + 3x = 18x[/tex]
e)
[tex]4x + 5y - 6x - 6y = - 2x - y[/tex]
f)
[tex]3x - 4xy + 5y + 3x + 4xy = \\ 6x + 5y[/tex]