Answer:
12 pounds
Explanation:
One quantity is asked for, so it is convenient to let a variable represent that. We can use x to represent pounds of chocolate. Then the total cost of the mix is ...
19.30·x + 3.50·18 = 9.82·(x +18) . . . . cost of chocolate + cost of trail mix
9.48·x = 113.76 . . . . . . simplify, subtract 63+9.82x
113.76/9.48 = x = 12 . . . . . . divide by the coefficient of x
The owner needs to mix 12 pounds of chocolate. (no rounding necessary)