A grocer wants to mix x pounds of cashew nuts worth $7.00 per pound with 9 pounds of peanuts worth $3.00 per pound to obtain 9+x pounds of mixture worth $5.00per pound. Total cost of cashews + Total cost of peanuts = Total cost.

Total cost of cashews + Total cost of peanuts = Total cost.

total cost of cashews=$7 * x=7x

total cost of peanuts=$3 * 9=27

total cost = (9+x) * $5=45+5x

7x+27=5x+45

subtract 5x from both sides:

2x+27=45

subtract 27 from both sides:

2x=18

x=9 pounds of cashews