we have the system
f+n=8 -----> f=8-n -----> equation 1
0.5f+1.5n=6 -----> equation 2
Solve the system of equations
Substitute equation 1 in equation 2
0.5(8-n)+1.5n=6
solve for n
4-0.5n+1.5n=6
n=6-4
n=2
Find out the value of f
f=8-n
f=8-2
f=6
therefore
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