Hey
If you let b = # of bracelets and D = amount donated to get a bracelet, then the total amount collected in donations would be number of people who donated and got a bracelet (b) times the amount of the suggested donation (D). So the expression would be...
b×D or bD
*note- we didn't include an equals sign or a variable for the answer because it asked for an expression and not an equation.
Hoped That Helped You