I forgot how to do it!

A

a13xz

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Sep 8, 2009
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Hi everyone :), I got some math review (I'm currently in grade 11- but it's review from 10) and I totally forgot how to do it!

The question is: 2y^2+11y+12

I did...
2y^2+11y+12
2(y^2+5.5y+6)

And then I'm stuck. I vaguely remember squaring something, but I really need help!Thank you in advance!
-alex
 
a13xz said:
....and I totally forgot how to do it!
Click to expand...
Well, if you TOTALLY forgot what you learned a year ago, you need classroom help; not provided here.
 
a13xz said:
… The question is: 2y^2+11y+12 …

This is not a question! This is only an algebraic expression. (It's a 2nd-degree polynomial, to be more precise.)

You must have received some instruction with it. What IS the question?
Click to expand...


Hello Alex:

Your work shown makes me wonder if you're supposed to complete the square. But, who knows? :?

Are you able to form specific questions about why you're stuck (doing whatever it is that you're supposed to do)?

If I knew what you're thinking, perhaps I could help you.

If you think you need review on completing the square, there is plenty of information, lessons, and examples on the Internet.

We're here to help students with specific questions.

Cheers ~ Mark

 
a13xz said:
Hi everyone :), I got some math review (I'm currently in grade 11- but it's review from 10) and I totally forgot how to do it!

The question is: 2y^2+11y+12

I did...
2y^2+11y+12
2(y^2+5.5y+6)

And then I'm stuck. I vaguely remember squaring something, but I really need help!Thank you in advance!
-alex
Click to expand...


Maybe you are trying to factor this expression??

If so, then I would not begin by taking out a common factor of 2....2 is not an integral factor of 11y.

Rather, I'd approach it this way.

1) Multiply the coefficient of y^2 by the constant term. 2*12 = 24

2) Look for two numbers whose product is 24, and whose SUM is +11....the coefficient of the "y" term. 3 and 8 will work, because 3*8 = 24 and 3 + 8 = 11.

3) Re-write the middle term as 3y + 8y:

2y^2 + 3y + 8y + 12

4) Factor by grouping the first two terms together, and the last two terms together. The first two terms have a common factor of y, and the last two have a common factor of 4. Remove the common factor from each pair of terms:

y(2y + 3) + 4(2y + 3)

Now, (2y + 3) is a common factor in both terms. Remove it:

(2y + 3)(y + 4)

There's your factorization.

If I have misunderstood what you were supposed to do with this expression, I'm sorry....we can do a better job of helping you if we don't have to GUESS at what the directions for the problem were.
 
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