15(b). Two years ago, a man was five times as old as his grandson. Two years later, his age will be 12 more than three times the age of the grandson. The present age of the grandson is: \( \begin{array}{lll}\text { 1) } 15 \text { years } & \text { 2) } 12 \text { years } & \text { 3) } 14 \text { years }\end{array} \quad \) 4) 6 years

\( 0<a<b<c<d \) ve \( \frac{1}{a}+\frac{1}{b}+\frac{1}{c}+\frac{1}{d}=\frac{1}{4} \) olduğuna göre, a nın alabileceğı kaç farklı tam sayı değeri vardır?

При каком значение х график функции \( f(x)=\log _{3}(x-9) \) проходит через точку \( (x ; 3) ? \)

A) \( a^{2}-25=(a-5)(a+5) \)

(a) \( \frac{1}{2} \) \( \lim _{x \rightarrow-2} \frac{x^{2}-8 x+m}{x^{2}-4}=k \), then \( k+m= \) \( \begin{array}{ll}\text { (a) } 10 & \text { (b) } 11\end{array} \)

\( \frac{1}{a}+\frac{1}{b}+\frac{1}{c}+\frac{1}{d}=\frac{1}{4} \) olduğuna göre, a nın alabileceği kaç farklı tam sayı değeri vardır? \( \begin{array}{lllll}\text { A) } 5 & \text { B) } 6 & \text { C) } 8 & \text { D) } 9 & \text { E) } 11\end{array} \)