Simultaneous Equations - Elimination method Example 5 : ExamSolutions

[jimmygirlxx]

For the first equation, why did you choose number 2 and for equation 2 why did you choose number 3? Like could you choose any other numbers? Or is there a specific reason as to why you choose those to numbers at the start of the video? Sorry I'm struggling with maths 

[ExamSolutions]

@jimmygirlxx You aim to make the terms in x or the terms in y the same, so in the case of the x terms choose a number that 3 and 2 go into which is 6. You could choose 12, 18, etc but it is best to take the smalllest number as it makes the maths easier but you would still get the same answer. Best thing to do is experiment.

[jimmygirlxx]

@ExamSolutions But what if yo have an odd number? Like my equation is (1)3x+2y=-23 (2) 5x+2y=-29? Nothing can go into 5 about from 1?....

[ExamSolutions]

@jimmygirlxx They both go into 15 so times (1) by 5 to give 15x + 10y = -115 then times (2) by 3 to give 15x + 6y = -87 then subtract. However, why do this anyway as both the y terms are the same. Subtract and eliminate the y terms instead. a lot easier.

[crazybabes1991]

your question are easy to understand, but how if i want to eliminate y, but at the same time x also eliminated.? this are my question(1) 6x-2y=3 and(2) 15x-5y=4. i try to eliminate equation (1) by 6xX5=30x, 15xX2=30x, and equation (2) by 2yX5=10y, 5yX2=10y....

[ExamSolutions]

@crazybabes1991 What you have here is an equation that has no solution then. If you were to draw the graphs of these two equations you would get two parallel lines that have no point of intersection. So no solution. Hope that makes sense?

[crazybabes1991]

@ExamSolutions hi again... i already get the answer from my lecturer, she also said theres no solution. and i hope u can show how to draw the graph using no solution equation. i really enjoy using this method for my math solution. sorry my english are bad.

[hayda121]

OMD this was so helpful thank you so so much :D

[xXAceoFwingSXx]

So, what happens when y is the same on both equations? -.-

[OmgItsTurk]

living legend , like the status if you agree!

[SHINeeTaeminForever]

THANK YOU XD I FINALLY UNDERSTAND IT

[ridemeup]

Im a high school teacher and students were at first confused on how to do this simultaneous equation not until I've shown this video, they are now able to understand what has really going on =) THANK YOU VERY MUCH !!

[ExamSolutions]

@ridemeup No probs - pleased to be of service.

[carlhj]

Thank you so much!! I'm sooo glad I found this video! It helped me understand almost everything on Simultaneous equations: clear, straightforward and no waffling.

[ExamSolutions]

@carlhj Thank you.

[pedrofsantos]

thank you, very clear and straight to the point!

[ExamSolutions]

@pedrofsantos Thanks - pleased to hear you found it useful

[sbmla72]

this confused me :l

[p0giful]

tnx men

[ExamSolutions]

@p0giful cheers mate

[omnomnomtwo]

your videos are great, but if you don't mind me asking could you solve harder examples that pertain to the A level syllabus? for example, often i come across simultaneous equations where both equations = 0, and one equation's X and Y terms are squared..

[hotchickalert1]

tnx man u make de ting look soo easy,i just hope wen am in dah exam room i go remember everytin>..... big up to everybody doin cxc in trinidad

[hotchickalert1]

tnx dude u make it look much easier,i hope when am n dat exam room i'll remember everytin

[ExamSolutions]

Pleased to hear that.

[mychemfreak246]

THANK YOU!!! You've REALLY helped me out :)

[cdt97]

@mychemfreak246 isn t he a hunk