a )
x^3-7x^2+5=x^3-x+3x^2-2 (distribución del paréntesis)
x^3 - x^3+7x^2-3x^2+x+5+2=0 (se pasa todo con operacion contraria)
4x^2+x+7=0 ( grado 2)
b)
y^2-2y+5y-10=2y^2+2y-y-1+7
y^2+3y=2y^2+y+6
y^2-2y^2+3y-y-6=0
-y^2+2y-6=0 (grado 2)
c)
y^2+7=y^2-2y+1+3y
y^2+7=y^2+y+1
y^2-y^2-y+7-1=0
-y+6= ( grado 1)
d)
u^2-2u+1=u^2+u+3u+3+5
u^2-2u+1=u^2+4u+8
u^2-u^2-2u-4u+1-8=0
-6u-7=0 (grado 1)