Найдите алгебраическую сумму многочленов:
1) (5+4а^3)+(a+2a^3)
2) (y-7x^4)-(2,3-9x^4)
3) (9b+7c^2)-(14b-10c^2)
4) (39n^2-2m)+(5m-44n^2).

1) (5+4а^3)+(a+2a^3)=5+4а^3+а+2а^3=5+а+6а^3

2) (y-7x^4)-(2,3-9x^4)=у-7х^4-2,3+9х^4=у-2,3+2х^4

3) (9b+7c^2)-(14b-10c^2)=9b+7c^2-14b+10c^2=17c^2-5b

4) (39n^2-2m)+(5m-44n^2)=39n^2-2m+5m-44n^2=3m-5n^2