Resposta:
a) (-2a²-3a+6)-(-4a²-5a+6)=
[tex] - 2 {a}^{2} - 3a + 6 + 4 {a}^{2} + 5a - 6 \\ 2 {a}^{2} + 2a[/tex]
b) (4x³ - 6x² + 3x)-(7x³-6x² + 8x )
[tex]4 {x}^{3} - 6 {x}^{2} + 3x - 7 {x}^{3} + 6 {x}^{2} - 8x \\ - 3 {x}^{3} - 5x[/tex]
c) (x² + 2xy + y²) - (y² + x² + 2xy )
[tex] {x}^{2} + 2xy + {y}^{2} - {y}^{2} - {x}^{2} - 2xy \\ = 0[/tex]
d) (x²+5x+3)-(4x²+6)
[tex] {x}^{2} + 5x + 3 - 4 {x}^{2} - 6 \\ - 3 {x}^{2} + 5x - 3[/tex]
e) (7ab +4c-3a)-(5c+ 4a-10)
[tex]7ab + 4c - 3a - 5c - 4a + 10 \\ 7ab - c + 7a + 10[/tex]
