Maths C3 - F(x) = Q(x) X divisor + remainder.... HELP

Can someone explain the bit below where you're meant to compare the co-efficients?..

Click to enlarge...

(Taken from pg.9 of the Edexcel C3 Modular textbook)

Yes see the triple lined equal sign? that means exactly the same.

So you compare the coefficients.

For example Ax^2 +Bx $\equiv$ 5x^2 +2x

so when we compare the x^2 coefficients we understand that Ax^2$\equiv$ 5x^2

so we know A=5

with the textbook just see what multiplies to give every single x^2 terms then set that equal to the x^2 coefficient

you can do that for every single term and sometimes and easier way to do things is you can set x= whatever number to make some 0s so then you can find out that the coefficients are

I still don't understand. How come the numbers you've used are different to the ones in the text book?

How does comparing $x^3$ mean $1=A$ ??

I still don't understand. How come the numbers you've used are different to the ones in the text book?

How does comparing $x^3$ mean $1=A$ ??

I still don't understand. How come the numbers you've used are different to the ones in the text book?

How does comparing $x^3$ mean $1=A$ ??

that was just an example sorry

ok so we can get the $x^3$ term by multiplying $Ax^2\ by\ x$ the coefficient of $x^3$ on the left hand side is 1 so A must be 1

OMG you're amazing. I think I understand it now.

Is what you're explaining just like what is explained in this video?... https://www.youtube.com/watch?v=RNnRoTFA3fc

yes.... wtf they doing lol?

in that first example see to get all the x terms you have to multiply Ax by 2 and B by x so you get 2A+B=7 where the 7 on the left hand side is the x coefficient


Anyway as long as you understand it's all good.

Yes I definitely get it now. Thank you so much for the explanation. It was a rookie mistake but I am feeling much more refreshed today so hopefully I won't be silly again :P