I failed at solving this system of equations for an exam, it cost me 20 points out of 100, if only...

I failed at solving this system of equations for an exam, it cost me 20 points out of 100, if only... The worst thing is, this system was part of the easiest problem to solve in the exam, it was about finding the maximum of a function.

In general I have big problems solving this sort of basics things, like applying the proprieties of the exponential, even simplifying or factoring sometimes.

>tl;dr

Do you guys know a good source to improve my abilities and knowledge regarding this type of problems (basic Algebra)? Perhaps a particular book, or a website with series of excercises?

Just pick any pre-calculus book.

Did you at least finish it when you got it back???
Show us your power level.

I thought about that, but which one guarantees me from achieving my learning goals faster or more efficiently?

It would be great to get a personal recommendation.

Yes I did, got y=0 z=0

Easy af ;__; but while I was taking the exam I ended up with a long equation with big numbers, that of course would have gotten me to the question but, you know, there was an easier way

Actually it wasn't that easy for me at that moment. Also is not the first time I ruin my score for something like this.

You missed the "real" solution.

Once you factor out the y's and z's from each equation (i.e. the 0 solution), you're left with a very basic pair of linear equations any child should be able to solve.

I'm terribly sorry bud, but that's not... it...
Factorize out everything you can, then you can eliminate what you want assuming those equations were actually equal to zero. From there it's a simple system which should be clear enough.

You should really practice these. Most of high school will remain like this, simply getting harder with some calculus later on and simple vectors.

How old are you?

post step by step solution you god damn retard. I made this shitty thread and you dont help at all faggot

z^2(20-2y-z)=0
yz(40-2y-3z)=0
Suppose z = 0, then y can be any number, and the equations are satisfied. If z is not equal to 0, then 10-z/2 = y must be true for equation 1 to be 0. If y happens to be 0 when z is not 0, then equation 2 becomes 0 as well (y=0,z=20). Now, suppose both z is not 0 and y is not 0, then the equations 10 - z/2 = y and 20-1.5z=y must be satisfied (the only pair that does this is y=5, z=10).

kek, He is not OP

I'm at the university at an engineering degree, I'm good at maths, but when it comes to simplier things like this most of the time I end up fucking it up.

Thanks for the resolution

21 ;___;

kek just reinforcing the meme

You are like a little baby

My tip is just practice like in that Heaton video where he tells you to practice

Also do yourself a favor and try to be humble

It's a nice mime actually

Thanks for the advices

>I'm at the university at an engineering degree
Holy fucking kek.

>getting engineering degree
>can't into basic math

You literally cannot make this shit up, famalam.

Basic math has always been a job for my calculator, even when trying to understand large proofs for important theorems.

How can you have understood any important theorems if you cannot factorize a polynomial

I can, but it takes me longer than it should, also my calculator would do it or I'd simply put in to wolfram

I sympathise with the OP.

Have none of you ever had a lagrange multiplier optimisation problem where you had to solve a system of say 4 or more non-linear simultaneous equations ?

It is NOT a trivial process that you can crank the handle and apply the same process to every single time and have it work out ok.
No, isolating one of the variables then substituting it into the remaining equations is not always possible or helpful.

There's a reason why solving non-linear equations simultaneously is not taught as a general method like solving simultaneous linear equations is in ntroductory linear algebra, and that is because there is no such general method.
It is purely ad-hoc and often the sets of non-linear simultaneous equations thatt need to be solved have to simply be given to some newton-raphson like process.

So yes , solving non-linear simultaneous equations can be hard, and don't have a general approach, andoften do require you to ad-hoc spot something clever that you're unlikely to ever spot or do again.

So people ITT acting like solving sets of non-linear simultaneous equations is trivial are faggots.

but as an addenda, this particular problem was easy.

I am attacking the idea that simultaneous non-linear equations in general are necessarily easy.

very often they are not