SOLUTION: Can u please help me solve this equation on quadratic equations: 5k^2+17k+6=0 I can do the quadratic equations without a constant infront of the k but i cant do the ones with a n

Algebra ->  Proportions  -> Lessons -> SOLUTION: Can u please help me solve this equation on quadratic equations: 5k^2+17k+6=0 I can do the quadratic equations without a constant infront of the k but i cant do the ones with a n      Log On


   

Question 6849: Can u please help me solve this equation on quadratic equations: 5k^2+17k+6=0
I can do the quadratic equations without a constant infront of the k but i cant do the ones with a number infront of the k. I would be grateful if u could help me
Thanks
Answer by longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
5k%5E2%2B17k%2B6=0 --> you need to do some mental arithmetic, that is all. For 5k%5E2, we will need 5k and k. Also for the 6, we will have either 1x6 or 3x2, if it is to be factorised... all you need do is write them down and look at them and figure out if any combination gives 17:

1x6
--> 5 lots of 6 is 30 + 1 is 31 --> too big to give 17
--> 5 lots of 1 is 5 then + 6 is 11 --> too small to give 17
2x3
--> 5 lots of 2 is 10 + 3 is 13 --> too small
--> 5 lots of 3 is 15 + 2 is 17 --> wayyy-heyyy!!!

So, the 5k has to be multiplied to the 3, to give 17. The answer is therefore (5k+2)(k+3) = 0

That is the process you need to use...write it down on paper to check your answers.

The worst kind of question is 12x%5E2 etc, as this could be 1x12, 2x6 or 3x4. You could be there for ages trying to figure it out :-)

jon.