Here are the solutions for adding the polynomials. To solve these, we group "like terms" together. Like terms are terms that have the exact same variable and exponent (for example, $x^2$ and $x^2$ go together, but $x^2$ and $x$ do not).
1) $(3x^2 + 9x + 2) + (4x + 3 - 5x^2)$
* Group $x^2$ terms: $3x^2 - 5x^2 = -2x^2$
* Group $x$ terms: $9x + 4x = 13x$
* Group numbers: $2 + 3 = 5$
*
Result: $-2x^2 + 13x + 5$
2) $(4a^3 + a^2 - 8a^2 + a + 6) + (-4a^3 + a^2 - 8a + 6)$
* Group $a^3$ terms: $4a^3 - 4a^3 = 0$
* Group $a^2$ terms: $a^2 - 8a^2 + a^2 = -6a^2$
* Group $a$ terms: $a - 8a = -7a$
* Group numbers: $6 + 6 = 12$
*
Result: $-6a^2 - 7a + 12$
3) $(2m^2 + 5n^2 + 8mn) + (3n^2 + 10m^2 + 4mn + 2n^2)$
* Group $m^2$ terms: $2m^2 + 10m^2 = 12m^2$
* Group $n^2$ terms: $5n^2 + 3n^2 + 2n^2 = 10n^2$
* Group $mn$ terms: $8mn + 4mn = 12mn$
*
Result: $12m^2 + 10n^2 + 12mn$
4) $(7c^2 - 2bc + 4b^2 + c^2) + (-c^2 - 2b^2 + 5bc)$
* Group $c^2$ terms: $7c^2 + c^2 - c^2 = 7c^2$
* Group $bc$ terms: $-2bc + 5bc = 3bc$
* Group $b^2$ terms: $4b^2 - 2b^2 = 2b^2$
*
Result: $7c^2 + 3bc + 2b^2$
5) $(8p^2 - 6p^2 + 4p - 4 + 6p^2) + (8p^2 - 6p - 6p^2)$
* Group $p^2$ terms: $8p^2 - 6p^2 + 6p^2 + 8p^2 - 6p^2 = 10p^2$
* Group $p$ terms: $4p - 6p = -2p$
* Group numbers: $-4$
*
Result: $10p^2 - 2p - 4$
6) $(-2xy^2 + 6y + 14y^2 + 4y^2) + (2y^2 + y^2 - 5y)$
* Group $xy^2$ terms: $-2xy^2$ (no other like terms)
* Group $y^2$ terms: $14y^2 + 4y^2 + 2y^2 + y^2 = 21y^2$
* Group $y$ terms: $6y - 5y = y$
*
Result: $-2xy^2 + 21y^2 + y$
7) $(-r^2 + 5rs + 2s^2 + 6) + (-5 + r^2 + 2s^2 - 5rs)$
* Group $r^2$ terms: $-r^2 + r^2 = 0$
* Group $rs$ terms: $5rs - 5rs = 0$
* Group $s^2$ terms: $2s^2 + 2s^2 = 4s^2$
* Group numbers: $6 - 5 = 1$
*
Result: $4s^2 + 1$
8) $(6ab^2 + 2a^2 - b + 2d) + (3d - 5ab^2 + 2a - 5d^2)$
* Group $ab^2$ terms: $6ab^2 - 5ab^2 = ab^2$
* Group $a^2$ terms: $2a^2$
* Group $a$ terms: $2a$
* Group $b$ terms: $-b$
* Group $d$ terms: $2d + 3d = 5d$
* Group $d^2$ terms: $-5d^2$
*
Result: $ab^2 + 2a^2 + 2a - b + 5d - 5d^2$
Final Answer:
1) $-2x^2 + 13x + 5$
2) $-6a^2 - 7a + 12$
3) $12m^2 + 10n^2 + 12mn$
4) $7c^2 + 3bc + 2b^2$
5) $10p^2 - 2p - 4$
6) $-2xy^2 + 21y^2 + y$
7) $4s^2 + 1$
8) $ab^2 + 2a^2 + 2a - b + 5d - 5d^2$
Parent Tip: Review the logic above to help your child master the concept of adding polynomials worksheet answers.