Помогите пожалуйста с примерами!

А)
$- 8 {p}^{4} + 12 {p}^{3} + 4 {p}^{4} - 8 {p}^{2} + 3 {p}^{2} = - 4 {p}^{4} + 12 {p}^{3} - 5 {p}^{2}$
б)
$2a {a}^{2} + {a}^{2} - 3 {a}^{2} + {a}^{3} - a = 2 {a}^{3} + {a}^{2} - 3 {a}^{2} + {a}^{3} - a = 3 {a}^{3} - 2 {a}^{2} - a$
в)
$3x {x}^{4} + 3x {x}^{3} - 5 {x}^{2} {x}^{3} - 5 {x}^{2}x = 3 {x}^{5} + 3 {x}^{4} - 5 {x}^{5} - 5 {x}^{3} = - 2 {x}^{5} + 3 {x}^{4} - 5 {x}^{3}$
г)
$3a \times 4 {b}^{2} - 0.8b \times 4 {b}^{2} - 2ab \times 3b + b \times 3 {b}^{2} - 1 = 12a {b}^{2} - 3.2 {b}^{3} - 6a {b}^{2} + 3 {b}^{3} - 1 = - 0.2 {b}^{3} + 6a {b}^{2} - 1$