Question 986172
If the help needed is to make the system of equations, then that would usually be the kind of help given for this.  If the help needed is to solve the system, then taking a step back to the more fundamental algebra is what is really needed.


Two linear equations in the two unknown variables, s and c.
{{{system(3s+2c=11.05,2s+c=6.5)}}}


Most comfortable method would be Elimination.  Simplest way here without explanation is the equivalent:
{{{system(3s+2c=11.05,4s+2c=13)}}}, allowing for elimination of c to solve first for s.


{{{highlight(s=1.95)}}}
Do you see how?



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(Adjusted earlier mistake)