factoring using the zero principle
- Thread starter rage
- Start date
Your leading coefficient is not 1. That makes it a wee bit trickier.
Find 2 numbers when added equal -39 and when multipled equal -40
It's -40 because of the leading coefficient 5. 5(-8)=-40
\(\displaystyle \L\\a+b=-39\)
\(\displaystyle \L\\ab=-40\)
Solve this and we see that we have 1 and -40.
See?.
\(\displaystyle \L\\5k^{2}+k-40k-8\)
\(\displaystyle \L\\(5k^{2}+k)-(40k+8)\)
\(\displaystyle \L\\k(5k+1)-8(5k+1)\)
\(\displaystyle \L\\(k-8)(5k+1)\)
See, that/s not difficult. Is it?. Now, you try.
Find 2 numbers when added equal -39 and when multipled equal -40
It's -40 because of the leading coefficient 5. 5(-8)=-40
\(\displaystyle \L\\a+b=-39\)
\(\displaystyle \L\\ab=-40\)
Solve this and we see that we have 1 and -40.
See?.
\(\displaystyle \L\\5k^{2}+k-40k-8\)
\(\displaystyle \L\\(5k^{2}+k)-(40k+8)\)
\(\displaystyle \L\\k(5k+1)-8(5k+1)\)
\(\displaystyle \L\\(k-8)(5k+1)\)
See, that/s not difficult. Is it?. Now, you try.
- Joined
- Feb 4, 2004
- Messages
- 16,583
If the fully-worked solution didn't help at all, then you need more in-depth instruction than we can provide here. (We can help students work through specific exercises, but only when the student has a general grasp of the underlying material. We can't teach the course's material within this environment.)rage said:
Please consider spending a few hours studying some online lessons, or else hiring a personal tutor with whom you can work face-to-face, in order to get caught up on the course content.
My best wishes to you.
Eliz.