每日一题

Mathematics>Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer.

If the function f is defined by f(x)= (2x) + 3, and if f(a) = 11, what is the value of a?

(A) 4
(B) 7
(C) 11
(D) 17
(E) 25

答案和解析

答案：A

解析：

If the function f is defined by f(x)= (2x) + 3, and f(a) = 11, then f(a) = (2a) + 3 = 11. Therefore, a = (11-3)/2 = 4.