Help Factor polynomial??

Question

1) x^2 - x - 72

2) a^2+20a + 64

3) 10m^3n^2 - 15m^2n + 25m

Answer 1

10m^3n^2 - 15m^2n -25m

=5m(2m^2 n^2-3mn-5)

=5m(mn+1) (2mn-5)

Answer 2

1) (x+8)(x-9)

2)(a+16)(a+4)

Not sure about 3.

Answer 3

2) a^2+20a + 64

a^2+4a+16a+64

a(a+4)+16(a+4)

(a+4)(a+16)

3)10m^3n^2 - 15m^2n + 25m

cannot be factored.

Answer 4

1) (x-8) (x+9)

2) (a+16) (a+4)

3) (5mn-5) (2m^2n-5m)

You might recheck the last one...

Good luck.

Answer 5

1.

(x - 9)(x + 8)

2.

(a + 4)(a + 16)

3.

5m(2m^2n^2 - 3mn + 5)

Assuming the sign on the last term is correct, this does not factor any further with real factors.