Santana wants to give one-thenths of all his marbles plus eight to his brother. which expression can santana use to calculate how many of his total marbles (m) he wants to give to his brother

For this case we have the following variable:
 m = Santana's total marbles
 We must write an expression as a function of m to model the problem.
 "Santana wants to give one-thenths of all his marbles plus eight to his brother"
 The function is:
 f (m) = (1/10) m + 8
 
 An expression that Santana can use is:
 f (m) = (1/10) m + 8

Iam pretty sure its a sorry if im wrong