Thread: solutions to system of equations

find all solutions to the following equations. How do I do this???

x1+2x+x3+x4=7
x1+2x2+2x3-x4=12
2x1+4x2+6x4=4

You have 4 unknowns and 3 equations which means your solution will not be unique. Are you aware of this?

wait...so how do I solve it?

It can't be solved for a unique solution, before we go any further, take a look at this equation inparticular

Originally Posted by Taurus3

x1+2x+x3+x4=7

Is it

$\displaystyle \displaystyle x_1+2x_2+x_3+x_4=7$

or

$\displaystyle \displaystyle x_1+x_2+x_3+x_4=7$

??

The real question is, how have you learned to solve problems like these? There are a number of ways of solving such equations, ranging from fairly basic (eliminate variables by subtracting) to very sophisticated (row reduce the augmented matrix). Without more information, we cannot possibly know what woul be appropriate for you.