✨ คำตอบที่ดีที่สุด ✨
有點複雜。
f(1) = 2
f(2) = 4
f(3) = 6
f(2x+3) = f(x) + 7
f(45) if 2x+3 = 45, x = 21
f(45) = f(21) + 7
f(21) if 2x+3 = 21, x = 9
f(21) = f(9) + 7
f(9) if 2x+3 = 9, x = 3
f(9) = f(3) + 7 = 6 + 7 = 13
依序套回去
f(21) = f(9) + 7 = 13 + 7 = 20
f(45) = f(21) + 7 = 20 + 7 = 27
謝謝你！