stuck on that one and the following -
63w^2-89w+30 (factor it out)
stuck on that one and the following -
63w^2-89w+30 (factor it out)
(7w-6)(9w-5); 7x9=63; so try factors of 30: both are of the same sign (-), since the last term is + and the middle term is (-). 10x3 doesn't work, so 6 and 5 work; 6x9=54 and 5x7=35, adding to 89.
thank you! we had worked through all the problems, but for some reason got stuck on these two. Appreciate it!
- Jill O. from Republic, MO 3/19/2013ax2 + bx + c = a(x - x1)(x - x2) , x1 and x2 are roots of equation
ax2 + bx + c = 0 and x1,2 = (-b ± √D)/2a , D = b2 - 4ac
~~~~~~~~~~~
55n2 - 52n + 12 = 0 , D = 522 - 4 · 55 · 12 = 64
n1 = (52 + 8)/110 = 6/11
n2 = (52 – 8)/110 = 2/5
55(n – 6/11)(n – 2/5) = (11n – 6)(5n – 2)
(11n + 3)(5n + 4)
The key here is recognizing that 55 is the product of two (and two only) primes - 5 and 11. The rest of the problem works itself out
Comments
Hi Jill. I did some work to show you the universal method for factorize the trinominal, but it did not go through the right answer is (11n-6)(5n-2)
- Nataliya D. 3/19/2013thank-you! We understood the concept, but had two problems that we just couldn't figure out. I have a feeling it was a long day problem.... thanks for the help
- Jill O. from Republic, MO 3/19/2013