Resposta:
a) A+B=
[tex]8 {x}^{2} - 7x - 5 + 3 {x}^{2} - 4x + 2 \\ 11 {x}^{2} - 11x - 3[/tex]
b) A+B+C=
[tex]8 {x}^{2} - 7x - 5 + 3 {x}^{2} - 4x + 2 + ( - 2 {x}^{2} + 9x + 3) \\ 11 {x}^{2} - 11x - 3 - 2 {x}^{2} + 9x + 3 \\ 9 {x}^{2} - 2x[/tex]
c) B-A=
[tex]3 {x}^{2} - 4x + 2 - (8 {x}^{2} - 7x - 5) \\ 3 {x}^{2} - 4x + 2 - 8 {x}^{2} + 7x + 5 \\ - 5 {x}^{2} + 3x + 7[/tex]
d) C-B-A=
[tex] - 2 {x}^{2} + 9x + 3 - (3 {x}^{2} - 4x + 2) - (8 {x}^{2} - 7x - 5) \\ - 2 {x}^{2} + 9x + 3 - 3 {x}^{2} + 4x - 2 - 8 {x}^{2} + 7x + 5 \\ - 13 {x}^{2} + 20x + 6[/tex]
e) A+C
[tex]8 {x}^{2} - 7x + 5 + ( - 2 {x}^{2} + 9x +3 ) \\ 8 {x}^{2} - 7x + 5 - 2 {x}^{2} + 9x + 3 \\ 6 {x}^{2} + 2x + 8[/tex]
f) A-C=
[tex]8 {x}^{2} - 7x + 5 - ( - 2 {x}^{2} + 9x + 3) \\ 8 {x}^{2} - 7x + 5 + 2 {x}^{2} - 9x - 3 \\ 10 {x}^{2} - 16x + 2[/tex]
g) B-C=
[tex]3 {x}^{2} - 4x + 2 - ( - 2 {x}^{2} + 9x + 3) \\ 3 {x}^{2} - 4x + 2 + 2 {x}^{2} - 9x - 3 \\ 5 {x}^{2} - 13x - 1[/tex]
h) B-A-C=
[tex]3 {x}^{2} - 4x + 2 - (8 {x}^{2} - 7x - 5) - ( - 2 {x}^{2} + 9x + 3) \\ 3 {x}^{2} - 4x + 2 - 8 {x}^{2} + 7x + 5 + 2 {x}^{2} - 9x - 3 \\ - 3 {x}^{2} - 6x + 4[/tex]
i) B+C=
[tex]3 {x}^{2} - 4x + 2 + ( - 2 {x}^{2} + 9x + 3) \\ 3 {x}^{2} - 4x + 2 - 2 {x}^{2} + 9x + 3 \\ {x}^{2} + 5x + 5[/tex]
j) B-C=
[tex]3 {x}^{2} - 4x + 2 - ( - 2 {x}^{2} + 9x + 3) \\ 3 {x}^{2} - 4x + 2 + 2 {x}^{2} - 9x - 3 \\ 5 {x}^{2} - 13x - 1[/tex]
k) C-A=
[tex] - 2 {x}^{2} + 9x + 3 - (8 {x}^{2} - 7x - 5) \\ - 2 {x}^{2} + 9x + 3 - 8 {x}^{2} + 7x - 5 \\ - 10 {x}^{2} + 16x - 2[/tex]
l) 2A+3B-4C=
[tex]2 \times (8 {x}^{2} - 7x - 5) + 3 \times (3 {x}^{2} - 4x + 2) - 4 \times ( - 2 {x}^{2} + 9x + 3) \\ 16 {x}^{2} - 14x - 10 + 9 {x}^{2} - 12x + 6 + 8 {x}^{2} - 36x - 12 \\ 33 {x}^{2} - 62x - 16[/tex]
