Question 894005
{{{m=8+2j}}}, Johns mother is 8 more than twice his age;
{{{f=3+m}}}, His father is three years older than his mother is.;
{{{j+m+f=94}}}, the three family members have lived a total of 94 years.


That is a system of three linear equations in three unknown variables.  Handle the solution any way you want:  Substitution, Elimination, or Matrix Operations.



Using matrix row operations, I found <b>f=36, j=25, m=33</b>


Starting matrix in form f,j,m,C:
{{{(matrix(3,4,
0,1,-1,-8,
1,0,-1,3,
1,1,1,94))}}}


Final matrix after the row operations :
{{{(matrix(3,4,1,0,0,36,0,1,0,25,0,0,1,33))}}}