Solve the system using a matrix 1

Question

Solve the system

x₁+x₂-4x₃=3

3x₁+4x₂+3x₃=-8

 

x1=

x2=

x3=

Answer 1

Dalia,

 

It's not possible to do this by hand for three variables unless you have three equations. However, if you use Excel Solver you eventually get:

 

x1=-.42

x2=-.87

x3=-1.07

 

Be sure to unset the constraint for nonnegative integers! Your constraints are that the sum of the combinations are equal to 3 and -8 respectively and your target cell is either one of the sum of the combinations. Do send a snapshot of your Excel solver setup if you have questions.

 

Hope that helps,

Deanna