quadratics

[drowsy creek]

i dont undertsnad the what it wants or how to do it

<@&791435371564892232>

@spice wasp please.

@undone adder :))

[spice wasp]

expand the right hand side and compare coefficients

[drowsy creek]

ok lemme do that rq

[drowsy creek]

i got x^2 - ax - ax + a + b

for the right hand side

[spice wasp]

ok so u have -2ax if u simplify it

[drowsy creek]

yes

[spice wasp]

u see on the left the number in front of the x is -10

[drowsy creek]

yes

[spice wasp]

and on the right it is -2a

so this means -2a=-10

then u can find a

[drowsy creek]

so a is 5

[spice wasp]

yes

[drowsy creek]

what about the extra + a

[spice wasp]

it should be a^2 i believe

when you expand

[drowsy creek]

ohh yh mb

@spice wasp but what do i do w that?

[spice wasp]

So now we compare terms without x in them

So a^2 + b = 18

we know what a is so we can sub it in and solve for b

[drowsy creek]

i dont really get this bit

c is 18

[spice wasp]

look at the left hand side

[drowsy creek]

yes

[spice wasp]

the only term without x in front is 18

[drowsy creek]

ok

[spice wasp]

now on the right hand side the only bits without x in front are a^2 + b

[drowsy creek]

ohhhh

okok

[spice wasp]

so we make them equal

[drowsy creek]

i get it now

tysm ro

[spice wasp]

np

[drowsy creek]

@spice wasp do u mind helping with this one too?

you cna just about see the graph

[spice wasp]

are the roots at -3 and 5

[drowsy creek]

yes

[spice wasp]

ok so what u do is expand (x+3)(x-5)

[drowsy creek]

ill do that rq

[drowsy creek]

x^2 + 8x + 15

is b just 8 and c 15

[spice wasp]

yes

[drowsy creek]

omg tysm

i wouldve never thought of that

[drowsy creek]

how do you always know what to do

[spice wasp]

basically if u have a quadratic with roots a and b u can write it as (x-a)(x-b) so i did (x-(-3)(x-5) and i got (x+3)(x-5) btw this method only works if there isnt a number infront of the x^2

[drowsy creek]

hmmm okokk

tyy

[drowsy creek]

im ashamed to ask but could you please give me a little push towards the right direction?

@spice wasp i think its something to do with the 3 timestable

[spice wasp]

the top can be factorised into (x-3)(x+3) and the bottom can be factorised into x(x+3) so u can cancel the (x+3)s

[drowsy creek]

you make it look so ez

ty once again

[spice wasp]

the top is what is known as a difference of two squares

u should watch vids/read about it

and and the bottom u notice that both terms have an x u should tried to factor it out

[vale thicket]

complete the square

[drowsy creek]

ty but i some1 alreayd helped me out with that

BUT

could you hlp[e me out wit this pls @vale thicket

[main sundial]

Where do you do your past papers?

Online or on IPad?

[drowsy creek]

i do them on a computer

why?>

[main sundial]

Typing or?

[drowsy creek]

i write the answers in my book

[main sundial]

because I want to do past papers without printing or rewriting the question.

[drowsy creek]

this is homework not a past paper 😭

[main sundial]

Ok

[drowsy creek]

if you find a way can you tell me too

[main sundial]

I just use my iPad.

[drowsy creek]

oh

@vale thicket pllls

@main sundial do yk how to do this question?

[main sundial]

I ain’t even revised circle theorems. I’m revising quadratic simultaneous equations rn,

[drowsy creek]

im pretty sure this is quadratic simultaneous

[main sundial]

idk