Respuesta:
dificil , pero va
Explicación paso a paso:
[tex]7x^4-5x^5+4x^2-7+\left(x^3-3x^2-5+x\right)-\left(-3x^4+5-8x+2x^3\right)\\\\=7x^4-5x^5+4x^2-7+x^3-3x^2-5+x-\left(-3x^4+5-8x+2x^3\right)\\\\=-\left(-3x^4+5-8x+2x^3\right)-5x^5+7x^4+x^3+4x^2-3x^2+x-12\\\\=-\left(-3x^4+5-8x+2x^3\right)-5x^5+7x^4+x^3+x^2+x-12\\\\=3x^4-5+8x-2x^3-5x^5+7x^4+x^3+x^2+x-12\\\\=-5x^5+3x^4+7x^4-2x^3+x^3+x^2+8x+x-17\\\\=-5x^5+10x^4-x^3+x^2+8x+x-17\\\\x =-5x^5+10x^4-x^3+x^2+9x-17[/tex]
listo saludos!! corona:)
