Can someone please double check my work?
I'm factoring completely for these and I'd like to know if I did them properly before turning in for a grade.
1)
3x^2 + 17x + 10
= (3x + 2)(x + 5)

2)
5y^8 - 125
= 5(y^8 - 25)
= 5(y^4 + 5)(y^4 - 5)

3)
a^2 - 2ab - 15b^2
= (a - 5b)(a + 3b)

4)
4c^2 - 12c + 9
= (2c - 3)(2c - 3)

5)
p^4 - 1
= (p^2 + 1)(p^2 - 1)

6)
6y^2 - 54
= 6(y^2 - 9)
= 6(y + 3)(y - 3)

7)
x^2 + 10x + 21
= (x + 7)(x + 3)

8)
a^2 - 10ab + 3b^2
= cannot be factored

9)
5x^2 - 10x
= 5x(x - 2)

10)
x^2 + 12xy + 35y^2
= (x + 7y)(x + 5y)

Question

Can someone please double check my work?
I'm factoring completely for these and I'd like to know if I did them properly before turning in for a grade.
1)
3x^2 + 17x + 10
= (3x + 2)(x + 5)

2)
5y^8 - 125
= 5(y^8 - 25)
= 5(y^4 + 5)(y^4 - 5)

3)
a^2 - 2ab - 15b^2
= (a - 5b)(a + 3b)

4)
4c^2 - 12c + 9
= (2c - 3)(2c - 3)

5)
p^4 - 1
= (p^2 + 1)(p^2 - 1)

6)
6y^2 - 54
= 6(y^2 - 9)
= 6(y + 3)(y - 3)

7)
x^2 + 10x + 21
= (x + 7)(x + 3)

8)
a^2 - 10ab + 3b^2
= cannot be factored

9)
5x^2 - 10x
= 5x(x - 2)

10)
x^2 + 12xy + 35y^2
= (x + 7y)(x + 5y)

anonymous · Answer

nr5.

p^4 - 1
= (p^2 + 1)(p^2 - 1)

you can still use:
(p^2+1)(p-1)(p+1)  ...

kropot72 · Answer

All your answers look good to me. Well done!

anonymous · Answer

look good to me too. :)

anonymous · Answer

Thank you so much!

anonymous · Answer

don't forget to change that number 5...

campbell_st · Answer

it depends on how far you want to factorise

Question 5 has a solution by (p^2 + 1)(p^2 -1)

this can be further factorised to 

 (p^2 +1)(p+1)(p-1)

Question 4 can be simplified to  (2c - 3)^2