factoring help please for algebra.. :)?

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x(x+25)+a(x+25)=(x+a)(x+25)

x^2 + 25x + ax + 25a
= x(x + 25) + a(x + 25)
= (x + a)(x + 25)

It's (x+a)(x+25) but not squared.

x+5x+ax+5a

you have to find what is their gcf

x (x + 25) + a (x + 25)
(x + 25)(x + a)

(x + a)(x + 25)

People have already answered this so I won't bother. But, for some extra practice with factorising (as we call it here in Australia) I recommend checkong out this site: http://www.mathsnet.net/asa2/2004/c12pracfac.html

It generates problems for you to factorise

Its how I got myself familiar with the process!

x^2+25x+ax+25a

The terms with the common variables "x" and "a" are already grouped together. So just factor them out. Factor out "x" first.

x(x + 25) + ax+25a

Now factor out "a"

x(x + 25) + a(x + 25)

The common term "x" and "a" have or is being multiplied to is "x + 25", so factor that term out.

(x + 25)(x + a) or (x + a)(x + 25)

It's better to put the term you factored out "(x + 25)" in front of "(x + a)". It's like math etiquette. It'll lead to the same answer, though.

There are no two common terms being multiplied together so you can never get (x + 25)^2. There was only ONE (x + 25) and ONE (x + a).

You can CHECK if you're right by multiplying your answer out again.

(x + 25)(x + a)

Use the FOIL method

x(x) + x(a) + 25x + 25a

x^2 + ax + 25x + 25a

Group common "x" and "a" together and it should look like the original equation.

x^2 + 25x + ax + 25a

When you factor, it's always good to check. It'll save you from losing a lot of points on future exams.