Posted by **Alex** on Sunday, February 4, 2007 at 12:38pm.

1.3x^2+17x+10

2.5y^8-125

3.a^2-2ab-15b^2

*Please help me.You have to factor by completing.

Let's look at #1:

3x^2 + 17x + 10

We have 2 and 5 as factors of the last term.

What combinations can we do to arrive at the middle term?

(3x + ?)(x + ?)

Let's try (3x + 5)(x + 2), which will be 3x^2 + 11x + 10. This is not what we want.

Let's try (3x + 2)(x + 5), which will be 3x^2 + 17x + 10. This IS what we want; therefore, we have found the factors of this trinomial.

Here's a few hints for the other two.

Hint for #2: First factor out 5. Then factor what's left.

Hint for #3: First factor (a - 5b). Can you determine the second factor?

I hope this will help.

## Answer This Question

## Related Questions

- factoring completly - can anyone help me with these: 3x2 + 17x + 10 5y8 - 125 a2...
- Math Please Help me!!! - 3x^2+17x+10 *You have to factor completley but I don't ...
- Algebra I - Thanks Reiny, but I'm still lost. I understand how you multipled by ...
- Algebra - (x)/(x-3)-4-(2x-5)/(x+2) I posted something before this, so now this ...
- Algebra - (x)/(x-3)-4-(2x-5)/(x+2) I posted something before this, so now this ...
- Algebra - Solve: 5x-3=11+12x; 17x-3=11; 17x-3+3=11+3= 17x=14; x= 14/17 is this ...
- Math Help - 3x^2 + 17x + 10 *I really don't get this but you have to factor ...
- to Ms. Sue - This is what I have x=1st interger 17-x= 2nd interger equation: x(x...
- math - 3x^2+17x+10 *you have to factor completley 51xcubed+12 Didn't I do this ...
- Algebra - The answer in the book however says -(5x^2-17x-9)/(x-3)(x+2) so I don'...

More Related Questions