system of equations/3 variables, need help

[chocoholic_1980]

i need help to solve this system of equations,
3r+s+t=1.1
-2r+2s-3t=3.4
r+5s+2t=5.3
the back of the book says the answer is,
r=0.1
s=1.2
t=-0.4
but i dont know how to get the answer

 

[Denis]

i need help to solve this system of equations,
3r+s+t=1.1
-2r+2s-3t=3.4
r+5s+2t=5.3
the back of the book says the answer is,
r=0.1
s=1.2
t=-0.4
but i dont know how to get the answer

Go here:
http://www.allaboutcircuits.com/vol_5/chpt_4/14.html

You'll first see how to solve with 2 unknowns (2 equations);
then you'll be shown how to do a 3 unknowns like yours.
Come back if you need further help

Hint: multiply your equations by 10 to get rid of decimal points:
30r + 10s + 10t = 11
-20r+ 20s - 30t = 34
10r + 50s + 20t = 53

Question: if you don't know how, why were you given the problem?

 

[stapel]

What methods do you have for solving systems? Can you use matrices?

Thank you.

Eliz.