Medals awarded if all completed and method shown :) (Simultaneous Equations) 1.) 3x+2y=11 2x- y=-3 2.) 5x-7y=27 3x-4y=16 3.) 2x- y=5 \(\frac{ x }{ 4 } + \frac{ y }{ 3 }\)=2 4.) 0.4x + 3y = 2.6 x - 2y = 4.6
There are a two methods to solve this : 1) Substitution method 2) Elimination method Which one would you prefer ?
Elimination method please :)
Well in the method of elimination we try to add and subract to get rid of one variable or find a particular variable. Lets see the first one, 3x+2y=11---(1) 2x- y=-3---(2) I would reccomend you to multiply eq(2) by 2 and then add those equations You will get x.
i get x=5 but when i put it into the equation it does not work..... :(
3x+2y=11 4x-2y=-6 ---------- I think you are doing it wrong :/ try doing it again :)
cant do it :( not good at this :/
You just have to add them nothing else @Chloeee_Harris
oh ive got it now, how would i do the next question?
What did you get x as ?
5/7
x=5/7 Now put x in eq(1) and find y :)
4 3/7 :)
how would i do the next question?
5x-7y=27 3x-4y=16
@Chloeee_Harris You got y wrong.
it says its correct on my answer sheet,
3x+2y=11 put x=5/7 3(5/7)+2y=11 @Chloeee_Harris
@Chloeee_Harris 43/7 ?
no \[4\frac{ 3 }{ 7 }\]
@Chloeee_Harris Oh i got it it is 4 3/7 or 31/7 Yeah right :)
sorry about that, thanks for helping me, could you do the second question?
5x-7y=27 3x-4y=16 Now lets see this We can multiply eq(1) by 3 and eq(2) by 5 and then subract. And get y :)
so what would be the answer to that ^
thanks :)
question 3?
or question 4?
2x- y=5 \[\frac{ x }{ 4 } + \frac{ y }{ 3 }=2 \] If you want to use elimination, you could multiply the second by 8 and subtract it from the first.
\[8 \times ( \frac{ x }{ 4 }+\frac{ y }{ 3 })=8 \times 2\] becomes \[2x+\frac{ 8 y }{ 3 }=16\]\[2x-y=5 \] Now subtract the second from first.
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