Add the following: a. 7a - 3b, -9a + 2b e. 3x - 4y - 7z, -4x + 3y + 2z e. x3+7x3y2, 2x4+5x3y2, 2x4-7x3y2 f. a3+b2, 2a2-3b2, 4b4+c7 b. 9a - 4y, -8a + 5y d. 4p2+5q2-c2, 2p2-3q2 f. 2a4-6ab3, -3a4+3ab3 h. 4x2y2-8z2, 7x2y2-3z2

$$
(7a - 9a) + (-3b + 2b)
$$

$$
-2a - b
$$
*   **جواب:** $\boxed{-2a - b}$

$$
(9a - 8a) + (-4y + 5y)
$$

$$
a + y
$$
*   **جواب:** $\boxed{a + y}$

$$
(3x - 4x) + (-4y + 3y) + (-7z + 2z)
$$

$$
-x - y - 5z
$$
*   **جواب:** $\boxed{-x - y - 5z}$

$$
(4p^2 + 2p^2) + (5q^2 - 3q^2) - c^2
$$

$$
6p^2 + 2q^2 - c^2
$$
*   **جواب:** $\boxed{6p^2 + 2q^2 - c^2}$

$$
(x^4 + 2x^4 + 2x^4) + (7x^3y^2 + 5x^3y^2 - 7x^3y^2)
$$

$$
5x^4 + 5x^3y^2
$$
*   **جواب:** $\boxed{5x^4 + 5x^3y^2}$

$$
(2a^4 - 3a^4) + (-6ab^3 + 3ab^3)
$$

$$
-a^4 - 3ab^3
$$
*   **جواب:** $\boxed{-a^4 - 3ab^3}$

$$
(a^4 + 2a^4) + (b^7 - 3b^7) + 4b^4 + c^7
$$

$$
3a^4 - 2b^7 + 4b^4 + c^7
$$
*   **جواب:** $\boxed{3a^4 - 2b^7 + 4b^4 + c^7}$

$$
(4x^2y^2 + 7x^2y^2) + (-8z^2 - 3z^2)
$$

$$
11x^2y^2 - 11z^2
$$
*   **جواب:** $\boxed{11x^2y^2 - 11z^2}$