Subtract the following. 1. 2a - 3b from 6a - 7b 2. a + b - c from 2a - 5b + 3c 3. -2a2 - b2 - 3c2 from 4a2 + 5b2 - c2 4. x - 2y - 3z from 2x + y + 3z 5. 3x2 - 2x from 5x2 + 2x

$$(6a - 2a) + (-7b + 3b)$$ $$4a - 4b$$

• جواب: $\boxed{4a - 4b}$

2. $a + b - c$ from $2a - 5b + 3c$

$$(2a - a) + (-5b - b) + (3c + c)$$ $$a - 6b + 4c$$

• جواب: $\boxed{a - 6b + 4c}$

3. $-2a^2 - b^2 - 3c^2$ from $4a^2 + 5b^2 - c^2$

$$(4a^2 + 2a^2) + (5b^2 + b^2) + (-c^2 + 3c^2)$$ $$6a^2 + 6b^2 + 2c^2$$

• جواب: $\boxed{6a^2 + 6b^2 + 2c^2}$

4. $x - 2y - 3z$ from $2x + y + 3z$

$$(2x - x) + (y + 2y) + (3z + 3z)$$ $$x + 3y + 6z$$

• جواب: $\boxed{x + 3y + 6z}$

5. $3x^2 - 2x$ from $5x^2 + 2x$

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

• جواب: $\boxed{2x^2 + 4x}$

6. $a - b$ from $a$

$$(a - a) + b$$ $$0 + b$$ $$b$$

• جواب: $\boxed{b}$

7. $a - b - c$ from $a - b$

$$(a - a) + (-b + b) + c$$ $$0 + 0 + c$$ $$c$$

• جواب: $\boxed{c}$

8. $a - b$ from $a + b$

$$(a - a) + (b + b)$$ $$0 + 2b$$ $$2b$$

• جواب: $\boxed{2b}$

9. $x^2 + 3x + 9$ from $x^2 + 6x - 1$

$$(x^2 - x^2) + (6x - 3x) + (-1 - 9)$$ $$0 + 3x - 10$$ $$3x - 10$$

• جواب: $\boxed{3x - 10}$

10. $12x^2 - 8x$ from $15x^2 - 10x + 7$

$$(15x^2 - 12x^2) + (-10x + 8x) + 7$$ $$3x^2 - 2x + 7$$

• جواب: $\boxed{3x^2 - 2x + 7}$