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Simultaneous Equation Graphically Help PLZ

Hey guys these questions IDK how to answer. Can someone please do an example so I can do the others by myself ?Screenshot 2021-12-27 at 12.53.19.png
(edited 2 years ago)
Original post by peteryoungy
Hey guys these questions IDK how to answer. Can someone please do an example so I can do the others by myself ?Screenshot 2021-12-27 at 12.53.19.png


You can use desmos.
Original post by peteryoungy
Hey guys these questions IDK how to answer. Can someone please do an example so I can do the others by myself ?Screenshot 2021-12-27 at 12.53.19.png

Where does it say they have to be answered graphically
Original post by schoolhelper
You can use desmos.

That won't help in an exam will it?
Original post by Muttley79
That won't help in an exam will it?

They could use it to check their answers I guess.
As it was under the section of Simultaneous Equation Graphically I thought it needed to answer graphically. Ok, I am not really sure how to answer. Can someone please do a demo, I will do the rest.
Reply 6
Original post by peteryoungy
As it was under the section of Simultaneous Equation Graphically I thought it needed to answer graphically. Ok, I am not really sure how to answer. Can someone please do a demo, I will do the rest.

Chuck it in desmos ,find intersections.
Or do it manually, by using your linear graph which is the y =mx +c thingy rearrange it for y or x , sub the equation which you just rearranged into your quadratic to find x or y depending on what your previously rearrnaged for. Once you got that value, sub it into any one of those equations to give x and y.
Try to solve the simultaneous equations first. And then show how many roots do the quadratic equations have by doing factorise or using quadratic formulae etc. You can draw their graphs with roots.
Can someone please do a demo, I will do the rest.

I can use it as a template.
Original post by peteryoungy
Can someone please do a demo, I will do the rest.

I can use it as a template.

If you just went to desmos.com and click on the graphical calculator its very easy, but heres a simple one with a quadratic equation and a linear equation. Hopefully no explanation is necessary
https://www.desmos.com/calculator/4xvaxaxkok
Original post by mqb2766
If you just went to desmos.com and click on the graphical calculator its very easy, but heres a simple one with a quadratic equation and a linear equation. Hopefully no explanation is necessary
https://www.desmos.com/calculator/4xvaxaxkok

But will i get the mark? If this was an exam question. I won't have desmos. I need to know how to do it algebraically.
Original post by peteryoungy
But will i get the mark? If this was an exam question. I won't have desmos. I need to know how to do it algebraically.

The textbook section says sketch / use geogebra (graphically) but to do it algebraically, rearrange it into a standard quadratic in one variable and check the discriminant.
(edited 2 years ago)
Original post by peteryoungy
Can someone please do a demo, I will do the rest.

I can use it as a template.

No we can't as it's against forum rules - this is GCSE
Original post by peteryoungy
But will i get the mark? If this was an exam question. I won't have desmos. I need to know how to do it algebraically.

Genuine question, do you have the textbook?
The two main worked examples (5&6) in section 3.3 cover drawing it and using the discriminant and mention using geogebra (desmos) as a tool.
Reply 15
Original post by peteryoungy
Can someone please do a demo, I will do the rest.

I can use it as a template.

Try searching it up on youtube,
I'm pretty sure TL maths cover this on youtube, if he doesn't my bad.
Quick example on how to do this, question on furthest to the left
(Here you either rearrange your linear equation to make either y or x the subject)
substitute y=2x +8 into your quadratic or equate it,
so it would be 2x+8=6x^2+3x-7
Find the 2 values of x since it's still a quadratic
Once you find the 2 values of x, substitute them into any two of the equations to give y since they intersect through the same y values
so you can either substitute into y=2x+8 or y=6x^2+3x+7 to give the 2 values of y.
I'm pretty sure I'm not supposed to tell you the answer, so all I did here were the steps
(edited 2 years ago)

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