Resposta:

a)2x²-9x+2-3x²+7x-1= [tex]-x^2-2x+1[/tex]

b) 5x² +5x-8-2x² + 3x-2= [tex]3x^2+8x-10[/tex]

c) 3x-6y +4-4x+2y-2= [tex]-x-4y+2[/tex]

d)5x²-7x+2-2x²+7x-1= [tex]3x^2+1[/tex]

e) 4x + 3y +1-6x-2y-9= [tex]-2x+y-8[/tex]

f) 2 x ³ + 5x²+4 x- (2 x ³-3 x ² + x = [tex]8x^2+3x[/tex]

g) 5x²-2ax + a 2-3 x ² + 2ax - a ²= [tex]2x^2[/tex]

Explicação passo a passo:

a)2x²-9x+2-3x²+7x-1=

[tex]2x^2-9x+2-3x^2+7x-1=\\2x^2-3x^2-9x+7x-1=\\-x^2-9x+7x+2-1=\\-x^2-2x+2-1=\\-x^2-2x+1[/tex]

b) 5x² +5x-8-2x² + 3x-2=

[tex]5x^2+5x-8-2x^2 + 3x-2=\\5x^2-2x^2+5x+3x-8-2=\\3x^2+5x+3x-8-2=\\3x^2+8x-8-2=\\=3x^2+8x-10[/tex]

c) 3x-6y +4-4x+2y-2=

[tex]\\3x-6y+4-4x+2y-2=\\=3x-4x-6y+2y+4-2\\=-x-6y+2y+4-2\\=-x-4y+4-2\\=-x-4y+2[/tex]

d)5x²-7x+2-2x²+7x-1=

[tex]=5x^2-2x^2-7x+7x+2-1\\=3x^2-7x+7x+2-1\\=3x^2+2-1\\=3x^2+1[/tex]

e) 4x + 3y +1-6x-2y-9=

[tex]=4x-6x+3y-2y+1-9\\=-2x+3y-2y+1-9\\=-2x+y+1-9\\=-2x+y-8[/tex]

f) 2 x ³ + 5x²+4 x- (2 x ³-3 x ² + x =

[tex]=2x^3+5x^2+4x-2x^3+3x^2-x\\=2x^3-2x^3+5x^2+3x^2+4x-x\\=5x^2+3x^2+4x-x\\=8x^2+4x-x\\=8x^2+3x[/tex]

g) 5x²-2ax + a 2-3 x ² + 2ax - a ²=

[tex]=5x^2-3x^2+a^2-a^2-2ax+2ax\\=2x^2+a^2-a^2-2ax+2ax\\=2x^2-2ax+2ax\\=2x^2[/tex]