# HW Help - Factoring Trinomials

• Apr 21st 2009, 12:45 PM
HamzaH
HW Help - Factoring Trinomials
Factor each trinomial, if possible. If the trinomial cannot be factored using integers, write prime.

I'm listing 5 problems because each type varies and there is a whole section about them on the worksheet not because I want you to do more of my homework for me (Worried). THANKS A LOT FOR THE HELP GUYS!!! Please try to explain your best I am truly grateful :D.

Both Positive #'s:

2b^2 + 10b + 12

One negative and one positive #:

4x^2 + 4x - 3

Both negative #'s:

8b^2 - 5b - 10

With = to some # problem??

3h^2 + 2h - 16 = 0

Word Problem, I find these very difficult =*[

Lauren dove into a swimming pool from a 15-foot-high diving board with an initial upward velocity of 8 feet per second. Find the time t in seconds in took Lauren to enter the water. Use the model of vertical motion given by the equation h= -16t^2 + vt + s, where h is height in feet, t is time in seconds, v is the initial upward velocity in feet per second, and s is the initial height in feet. (Hint: Let h = 0 represent the surface of the pool.)

Thanks again I really want to understand this but I find it very difficult (Headbang)
• Apr 21st 2009, 04:06 PM
stapel
Quote:

Originally Posted by HamzaH
Factor each trinomial, if possible....

I'm listing 5 problems because each type varies and there is a whole section about them on the worksheet....

To learn how to factor quadratics, try some online lessons. (Wink)

Quote:

Originally Posted by HamzaH
2b^2 + 10b + 12

Take the common factor of 2 out front:

2(b^2 + 5b + 6)

Then find factors of 6 that add up to 5. Use these numbers to factor the b^2 + 5b + 6.

Quote:

Originally Posted by HamzaH
4x^2 + 4x - 3

There's no common factor here, and you're stuck with the 4 in front. So look at the factors of (4)(-3) = -12 that add to +4. You're multiplying to a negative, so the numbers must have opposite signs. You're adding to a positive, so the larger factor will get the "plus" sign.

4x^2 - 2x + 6x - 3

Then factor in pairs.

Quote:

Originally Posted by HamzaH
8b^2 - 5b - 10

There is no common factor, so you're stuck with the 8 in front. So look for factors of (8)(-10) = -80 that add up to -5. You're multiplying to a negative, so the factors have opposite signs. You're adding to a negative, so the larger factor will get the "minus" sign.

Factor pairs:

1 and 80
2 and 40
4 and 20
5 and 16
8 and 10

Does any factor-pair work? If so, then factor. If not, then the polynomial is "prime".

Quote:

Originally Posted by HamzaH
3h^2 + 2h - 16 = 0

You don't have to factor here. Just plug the above into the Quadratic Formula to find the solutions.

(Or, if the instructions specify that you must factor, find the factors of (3)(-16) = -48 that add to +2. Hint: Use +8 and -6.)

Quote:

Originally Posted by HamzaH
Lauren dove into a swimming pool from a 15-foot-high diving board with an initial upward velocity of 8 feet per second. Find the time t in seconds in took Lauren to enter the water. Use the model of vertical motion given by the equation h= -16t^2 + vt + s, where h is height in feet, t is time in seconds, v is the initial upward velocity in feet per second, and s is the initial height in feet. (Hint: Let h = 0 represent the surface of the pool.)

They've given you that s = 15 and v = 8, so plug these values into the equation they've given you.

They've asked you to find the time t when h = 0. So plug "0" in for "h", and solve the equation for the values of "t". Only one will make physical sense (since you can't have negative time.)