Algebraaaaaaaaaaaaah!

[WTFIsAGleepglorp]

OK.

Trying to go through the answers to a 'rearranging equations' homework booklet.

I've got the answers in front of me and going through it line by line.

Making different letters the subject of the equation and all that jazz.

However, I've got to this one and I'm stumped.

Where did the pn go?

I understand that when the + a went to the other side of the = sign it became - a, however the pn has just disappeared! I mean WTF!!??

Can anyone explain what's happened?

Oh crap! I can't add pictures again.

Perhaps I can try again without the local wifi.

How did it go from

pn + pa = n squared + a

to

pa - a = n squared

Where did the pn go?

I think it might be a mistake?
I'm sure there are others who will confirm, or tell me I've done something stupid!

I agree with Winter that there is a mistake and her solution looks right to me.

So from the line

pn + pa = n^2 + a

subtract pn from both sides

pa = n^2 + a - pn

then subtract a from both sides

pa - a = n^2 - pn

then continue as shown by Winter.

Aww, thanks everyone.

That makes a lot more sense. Phew! 🤗