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# GCSE Simultaneus equation help please! watch

1. 6x+2y=-3
4x-3y=11

24x+8y=-12
24x-18y=66
+8y+18y=-12--66
26y=-78
y=-78/26=-3
and then i dont know how to find x?
I know there are many methods for this but could someone figure out my method and put me back on the riht track as i am lost. I would be grateful if someone could help me out.
Thanks.
2. (Original post by Mercea)
6x+2y=-3
4x-3y=11

24x+8y=-12
24x-18y=66
+8y+18y=-12--66
26y=-78
y=-78/26=-3
and then i dont know how to find x?
I know there are many methods for this but could someone figure out my method and put me back on the riht track as i am lost. I would be grateful if someone could help me out.
Thanks.
To find x just but your value for y back into one of the equations you started with and rearrange.
3. (Original post by Thinking_Aloud)
To find x just but your value for y back into one of the equations you started with and rearrange.
Sorry but i dont know how
4. to find x, just put the value you got for y into one of the equations you got in the question itself and work it out to get x.
to check your solutions are right, just substitute the values for x and y into one of the first equations and see if it works out
hope this makes sense. good luck!
5. (Original post by Thinking_Aloud)
To find x just but your value for y back into one of the equations you started with and rearrange.

so i basically pick on eqaution and the substitue? Will my answer for X be the same?
6. for example, if my answer was 5 for y, i would do
6x + 2x5=-3
6x=-3-10 etc....
THIS IS A HYPOTHETICAL SITUATION (i chose a random value for y)
7. (Original post by Mercea)
Sorry but i dont know how
Okay, so take:
4x-3y=11
You know that y=-3, so you change the y in the equation to -3, to get:
4x-(3*-3)=11
You work that out, then move the equation around so you get the 4x on one side and the numbers on the other. Then you can work out x.

*=multiplied

8. (Original post by Mercea)
so i basically pick on eqaution and the substitue? Will my answer for X be the same?
Yes, as long as it was one of the ones you were given at the start. The answer will be the same as they are simultaneous, they were created using the same values for x and y.
9. (Original post by Thinking_Aloud)
Okay, so take:
4x-3y=11
You know that y=-3, so you change the y in the equation to -3, to get:
4x-(3*-3)=11
You work that out, then move the equation around so you get the 4x on one side and the numbers on the other. Then you can work out x.

*=multiplied

Will X be 1/2?
10. (Original post by Thinking_Aloud)
Yes, as long as it was one of the ones you were given at the start. The answer will be the same as they are simultaneous, they were created using the same values for x and y.
11. (Original post by Mercea)
Will X be 1/2?
Yes.
If your worried about your answer you can always check it in the other equation, substitute in both x and y and see if you get the answer given.
12. (Original post by Thinking_Aloud)
Yes.
If your worried about your answer you can always check it in the other equation, substitute in both x and y and see if you get the answer given.
For the other eqaution i got X to be 1.5. so that is a half right?
Are you saying that i can substitute for any eqaution i was given originally?
13. (Original post by Thinking_Aloud)
Yes.
If your worried about your answer you can always check it in the other equation, substitute in both x and y and see if you get the answer given.

14. (Original post by turn-to-page394)
for example, if my answer was 5 for y, i would do
6x + 2x5=-3
6x=-3-10 etc....
THIS IS A HYPOTHETICAL SITUATION (i chose a random value for y)
15. (Original post by Mercea)
For the other eqaution i got X to be 1.5. so that is a half right?
Are you saying that i can substitute for any eqaution i was given originally?
A half is right, for the other equation you must have subtracted -6 instead of adding it to get -9 and not 3. Try it again and see if you get the right answer.
16. (Original post by Thinking_Aloud)
A half is right, for the other equation you must have subtracted -6 instead of adding it to get -9 and not 3. Try it again and see if you get the right answer.
6x+2y(-3)=-3
6x-6=-3
6x=-3+6
6x=3
x=3/6=1/2
I think i get it now. Thankyou for your help. I am grateful

Edit: Finally i get how to do the simultaneus equations fully.

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