find three values of k>0 such that x^2-6x+k can be factored
@zepdrix
Ummmm so for it to factor nicely, we need 2 numbers which: `Multiply to k` `Add to -6`
So ummmm
Oh I guess it's just as simple as choosing two numbers which add to -6. Then we multiply those numbers to give us k.
So we could use ummm... how bout, -4+ -2 = -6 right?
so we need -1 and 6 correct
or 1*-6
If we add those values, \[\Large -6+1\ne-6\]Hmm I think you're thinking backwards ^^ heh
oh i see it needs to equal -6 so yes we can use -4+-2
If our 2 numbers are -4 and -2, what would our k value be? It should be the product of those two numbers, yes?
we would get -4+-2=-6
-4 + -2 = -6 gives us that middle number that we needed. Now to find k, we use the same numbers but we multiply them: -4 * -2 = ?
8
Ok good! So there is a value of k>0 that will work for our equation.\[\Large x^2-6x+\color{orangered}{8}\quad=\quad (x-4)(x-2)\]
So our first answer is k=8. We need to come up with a couple more.
alright
One thing to keep in mind, since they're restricting the k value to be positive ( k > 0 ), our numbers will both have to be negative. (Since neg*neg = pos ) Can you think of two other negative numbers that add to -6 besides -4 and -2?
we could do -2 and-3
-2 + -3 = -5 Hmm that doesn't quite work.
1 and 6
waitt hat dosen't work either
You're still thinking multiplication silly :3
3 an3
-3-3
good good :) k = -3 * -3
and that would be 9
Ok good we've found 2 values! k=8 k=9
-1-5=-6
Good good good.
-1*-5=5
sorry for thinking multiplication to much lol
k=5 k=8 k=9 Yayyyy good job \c:/ you found them all!
thanks for the help
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