# Thread: Finding length of the missing side

1. ## Finding length of the missing side

Even though this is geometry it comes from my Algebra 2 class.

I believe that $\displaystyle 2x+3$ is the With so I guess that I have to find the length?
Area : $\displaystyle 2x^2+5x+3$

Area= L*W

Therefore $\displaystyle 2x^2+5x+3= 2x+3$ = Length?

2. ## Re: Finding length of the missing side

It should be $\displaystyle 2x^2+5x+3= (2x+3)\times L$ now divide it out.

3. ## Re: Finding length of the missing side

You know the length of the rectangle is $\displaystyle 2x+3$ and the area of the rectangle is $\displaystyle 2x^2+5x+3$ that means the breadth of the rectangle has to look like $\displaystyle ax+b$, therefore:
$\displaystyle (2x+3)\cdot(ax+b)=2x^2+5x+3$

Determine $\displaystyle a$ and $\displaystyle b$

4. ## Re: Finding length of the missing side

Originally Posted by pickslides
It should be $\displaystyle 2x^2+5x+3= (2x+3)\times L$ now divide it out.
$\displaystyle 2x^2=L-3x$ ?

5. ## Re: Finding length of the missing side

pickslides said divide ...

$\displaystyle L = \frac{2x^2+5x+3}{2x+3}$

6. ## Re: Finding length of the missing side

Originally Posted by skeeter
pickslides said divide ...

$\displaystyle L = \frac{2x^2+5x+3}{2x+3}$
$\displaystyle L=\frac{2x^2+3x}{1}$ or $\displaystyle 2x^2+3x$

7. ## Re: Finding length of the missing side

go learn how to do long division of polynomials ...

Polynomial Long Division

8. ## Re: Finding length of the missing side

Originally Posted by skeeter
go learn how to do long division of polynomials ...

Polynomial Long Division
Honestly I think Siron's method will suffice for now.

9. ## Re: Finding length of the missing side

Originally Posted by Quacky
Honestly I think Siron's method will suffice for now.
if you had bothered to check the link, you would have noticed that it also shows the factoring technique.

10. ## Re: Finding length of the missing side

Originally Posted by skeeter
if you had bothered to check the link, you would have noticed that it also shows the factoring technique.
I never denied that. But the subject of the page is on polynomial long division, and I think that's asking the OP to run before they walk. With the UK system, there are about 3 years of teaching between this, which is applying the knowledge of factoring, and polynomial division.

11. ## Re: Finding length of the missing side

Originally Posted by Quacky
Honestly I think Siron's method will suffice for now.
Well, NO method will suffice for now; the OP does not know basics and needs classroom help, period.