please help me again with my algebra , Thank you

Answer:
1)
[tex]2x {}^{2} + 3x + 2 + 3 {x}^{2} - 5x - 1[/tex]
[tex]5 {x}^{2} - 2x + 1[/tex]
2)
[tex]x {}^{2} - 4 - (12x {}^{2} + 4x - 6)[/tex]
[tex]x {}^{2} - 4 - 12x {}^{2} - 4x + 6[/tex]
[tex] - 11x {}^{2} - 4x + 2[/tex]
3)
[tex]6x {}^{2} + 3x - 4 + x {}^{2} - 7[/tex]
[tex]7x {}^{2} + 3x - 11[/tex]
4)
[tex]7x {}^{ 3} + 4x - 1 + 2x {}^{2} - 6x + 2[/tex]
[tex]7x {}^{3} + 2x {}^{2} - 2x + 1[/tex]
5)
5x⁴-4x³-3x-4+2x⁴+6x³-2x
7x⁴+2x³-5x-4
Just do the simple addition. Make sure to add like terms. For instance: Add 3x² with 2x² only, not with 3x and 2.
→ 2x² + 3x + 2 + 3x² - 5x - 1
→ 2x² + 3x² + 3x - 5x + 2 - 1
The law of subtraction is to subtract the smaller value from the larger value. But it is not necessary that it is always applicable. Its value can be positive, negative and zero (which varies with the given values).
→ x² - 4 - (12x² + 4x - 6)
There will be no change in sign during addition. But if you're doing subtraction change the signs.
→ x² - 4 - 12x² - 4x + 6 [ Product of (-)(-) is (+) and (+)(-) is (-) ]
→ x² - 12x² - 4x - 4 + 6
→ 6x² + 3x - 4 + x² - 7
→ 6x² + x² + 3x - 4 - 7
→ 7x³ + 4x - 1 + 2x² - 6x + 2
→ 7x³ + 2x² + 4x - 6x - 1 + 2
→ 5x⁴ - 4x³ - 3x - 4 - (-2x⁴ - 6x³ + 2x)
→ 5x⁴ - 4x³ - 3x - 4 + 2x⁴ + 6x³ - 2x
→ 5x⁴ + 2x⁴ - 4x³ + 6x³ - 3x - 2x - 4