factoring by grouping:
10x^2 + 2xy + 15x + 3y
answer :(5x - y)(2x + 3) ? if its not that is it a prime?

Question

factoring by grouping:
10x^2 + 2xy + 15x + 3y
answer :(5x - y)(2x + 3) ? if its not that is it a prime?

anonymous · Answer

You're very close. Why the - in (5x - y)?

anonymous · Answer

so its a plus i mess up the signs most the time

anonymous · Answer

if its not that then it has got to be prime

anonymous · Answer

I don't really remember how to factorize a polynomial equation so I can't think of a trick for you other than making sure your factors give the initial equation when expanded :-S

anonymous · Answer

hm ok  thank you m_charron2

campbell_st · Answer

look at 10x^2 and 2xy  the common factor is 2x  

so its 2x(5x + y)

now 15x +3y  common factor of 3

3(5x + 3y)

you have 2x(5x+y) + 3(5x + y)'

take (5x + y) as a factor leaves

(5x+y)(2x + 3)

anonymous · Answer

campbell i think yours is correct but why are they flipped backwards the answer?

anonymous · Answer

i got 2x+3   5x+y

anonymous · Answer

maybe it doesnt matter

campbell_st · Answer

order isn't important in multiplication   5 x 3 is the same as 3 x 5

anonymous · Answer

yeahh ok