Because cashews priced at 900 per pound were not selling a p

Because cashews priced at $9.00 per pound were not selling, a produce clerk decided to combine them with less expensive peanuts and sell the mixture for $7.00 per pound. How many pounds of peanuts, selling at $6.00 per pound should be mixed with 50 pounds of cashews to obtain such a mixture? Assign variables. Write and equation.

Solution

Let there be x pound of $6 per pound penut
Total pound = x + 50 pound

Total cost = 50*9 + x*6
which must be same as (50+x)*7
equate them:
(50+x)*7 = 50*9 + x*6
350 + 7x = 450 + 6x
x = 100
Answer: 100 pound