factor out 2
2(3a^2-4a-15)
hmm
trial and error
nope
fancy I-forgot-the-name way
multiply 3 and -15 to get -45
find y and t such that yt=-45 and y+t=-4
tricky
hmm
-9 and 5
split -4a into -9a and 5a
2(3a^2-9a+5a-15)
split and factor
2[(3a^2-9a)+(5a-15)]
factor oout common factors
2[3a(a-3)+5(a-3)]
epic reverse distribute, remmber ab+ac=a(b+c) the (a-3) is theh a part
2[(a-3)(3a+5)]
something
(2)(a-3)(3a+5)
(2)(3a+5)(a-3) is factored form
