How many pounds of nuts selling for $12 per lb and raisins selling for $6 per lb should a person combine to obtain 60 lb of a trail mix selling for $8 per lb

N=number of pounds of nuts
r=number of pounds of ratins

total is 60 pounds
n+r=60

selling for 8 dollars per pound
(12n+6r)/60=8

now we have
n+r=60 and
(12n+6r)/60=8
solve

second equation, multiplyboth sides by 60
12n+6r=480
first equation, tmes -6 and add
12n+6r=480
-6n-6r=-360+
6n+0r=120

6n=120
divide both sides by 6
n=20

sub
n+r=60
20+r=60
r=40

20 pounds of nuts
40 pounds of rasins