This is an example of solving a system of equations of two variables. We let s be the number of seals purchased and b be the number of bears purchased. Then we know that .22s+.29b = 5.39 since you pay .22 per seal, .29 per beat, and 5.39 total.

Normally one would expect some more info such as the total number of items purchased was ____ ..... in this case, we know that

and

since some of each item were bought. You can play around with different values for s and b now to find s=10 and b=11

(normally you wouldn't have to play around with values because normally they would have told you a total of 21 items were purchased)