Marshall bought 32 ounces of mixed nuts, which are estimated to be 30%. which expression can be used to find the percentage of peanut concentration of the final mix if he adds x ounces of peanuts?

First we get 30% ounces of peanuts in mixed nuts:
 (0.3) * (32) = 9.6
 To find the percentage of peanut concentration of the final mix if you add x ounces of peanuts:
 % of peanuts = ((x + 9.6) / (x + 32)) * (100)
 
 An expression can be used is:
 % of peanuts = ((x + 9.6) / (x + 32)) * (100)