HELP non linear equations
posted by danni .
A company mixes peanuts, cashews, and almonds to obtain 22 oz package worth 6.91 dollars. If peanuts, cashews, and almonds cost 18, 45, and 50 cents per oz respectively, and the amount of cashews is equal to the amount of almonds, how much of each is in the package?

p+c+a = 22
a=c, so
p+2a=22
p = 222a
18p+45c+50a = 691
18(222a)+45a+50a = 691
a = 5, so
5 oz almonds
5 oz cashews
12 oz peanuts