Posted by **Jaz** on Tuesday, July 6, 2010 at 5:36pm.

Explain why x^2 +5x + 8 is prime(not factorable) How do you know?

Give 2 examples of a prime polynomial(can't be both binomials)

Give 2 examples of polynomials that are not prime(they can't be both binomials),factor them,explain what you did to factor them.

How would you explain to another student how to decide if any given polynomial is prime of not? Thanks

- Algebra -
**Damon**, Tuesday, July 6, 2010 at 7:15pm
a x^2 + b x + c

if sqrt (b^2-4ac) is a whole number then you can factor the quadratic

In this case b^2-4ac = 25 - 32 = -7

sqrt(-7) is an imaginary number so you can not factor this with whole numbers.

To make up some you can factor, do it backwards

for example

(x-1)(x-2) = x^2 -3x + 2

You know you can factor that.

Now one way to make up some you can not factor use big numbers at the end so that 4ac is positive and bigger than b^2

x^2 + 5 x + 100

- Algebra -
**Jaz**, Wednesday, July 7, 2010 at 1:43am
Damon, Thanks for your help. Appreciate it.

## Answer This Question

## Related Questions

- Algebra - Explain why x^2 + 5x + 8 is prime (not factorable). How do you know? ...
- math - The Twin Prime Conjecture, which has not been proven, argues that there ...
- Math(Please check answers) - Factor completely. If the polynomial cannot be ...
- Factoring and Prime - I am still having troulbe with these. Her is another one I...
- Math (Complex Numbers) - Let N be the sum of all prime powers that can be ...
- Algebra Please check answers - Could you please check these answers thanks. ...
- Math - Plz help dont know how to do this question. Write number 68 as a product ...
- math - If two numbers are relatively prime, what is their LCM? Explain the ...
- science - how is the equator similar to the prime meridian A. both the prime ...
- 8th grade math - If two numbers are relatively prime, what is their LCM? Explain...

More Related Questions