OpenStudy (anonymous):

I need help understanding the system of equations if someone is willing to explain it to me. Please and thank you.

4 years ago
OpenStudy (anonymous):

What do you want to know about them? Basically a system of equations is just a set of 2 or more equations. If you want to solve a system of equations you want to find what values for the variables make all of the equations true. Graphically what you're trying to do is find where the graphs of all equations in the system intersect.

4 years ago
OpenStudy (anonymous):

@BangkokGarret well I need to cover the 3 graph, substitution, and elimination

4 years ago
OpenStudy (wolf1728):

By 3 graph do you mean solving for 3 unknowns?

4 years ago
OpenStudy (anonymous):

the 3 system @wolf1728

4 years ago
OpenStudy (wolf1728):

You mean solving for 3 unknowns correct?

4 years ago
OpenStudy (anonymous):

Yeah I believe so

4 years ago
OpenStudy (wolf1728):

I chose a rather simple set of equations: x + y + z = 6 x -y +z =2 -2x + y -z = -3 We need to eliminate 1 of the unknowns so we add all 3 equations and get y + z = 5 This allows us to get a value of z = 5 -y and we substitute this into the first equation x + y + 5 - y = 6 x = 1 Now you would need to find y and z.

4 years ago
OpenStudy (anonymous):

hm Okay o:

4 years ago
OpenStudy (wolf1728):

Actually, I made an easy example. For instance the solving for the 'x' unknown usually involves multiplying or dividing equations by certain numbers so that 2 unknowns can be isolated. This is a lucky coincidence that 2 unknowns can get eliminated in one step.

4 years ago
OpenStudy (anonymous):

Just starting out and my online tutors don't really explain very well so Im trying here so hopefully I can understand it. but im understanding it well.

4 years ago
OpenStudy (wolf1728):

To solve for y and z we have to use 2 equations and substitute the value of x=1, and make sure that another unknown gets eliminated. Luckily the first 2 equations work quite nicely. 1 + y + z = 6 1 -y + z =2 y + z = 5 -y + z = 1 Adding the 2 equations 2 z = 6 z = 3 From the first equation x +y +z = 6 so plugging in the values of x and z 1 + y +3 = 6 y = 2 Remember, solving for 3 unknowns is rarely this easy.

4 years ago
OpenStudy (wolf1728):

Maybe it's just me but it appears my first posting got shifted into the next to the last posting.

4 years ago
OpenStudy (anonymous):

Well could u explain to me Systems of Linear Equations? I'm suppose to learn that for my oral assessment

4 years ago
OpenStudy (wolf1728):

You need a system of equations when solving for more than one unknown. For 2 unknowns, you need 2 equations, for 3 unknowns you need 3 equations, etc.

4 years ago
OpenStudy (anonymous):

ah that makes sense

4 years ago
OpenStudy (anonymous):

Can you give me an example of a word problem?

4 years ago
OpenStudy (wolf1728):

I think a Google search would turn up thousands of examples of word problems. Anyway, I must get going. Perhaps someone else will be able to help you out. :-)

4 years ago
OpenStudy (anonymous):

Well thank you anyways.

4 years ago
OpenStudy (phi):

see http://www.khanacademy.org/math/algebra/systems-of-eq-and-ineq/systems-of-eq-overview/v/trolls--tolls--and-systems-of-equations there are many videos on this topic

4 years ago