The sum of the numerator and the denominator of a fraction is 18 . If 1 is added to both its numerator and denominator, the reduced form of the new fraction so obtained is \( \frac{2}{3} \). Then, the original fraction is ........

9. Kasming maxrajini \( 6 a^{4} b^{3} \) ko' rinishiga keltiring. \( \begin{array}{lll}\text { 1) } \frac{a}{3 a b} & \text { 2) } \frac{2 a b^{2}}{a^{2} b} & \text { 3) } \frac{5 b}{15 a b^{4}}\end{array} \)

9. Meled the subject of the relation \( \mathrm{w}=\mathrm{M} \sqrt{\frac{\left(\mathrm{D}^{2}+\mathrm{d}^{2}\right)}{2 \mathrm{~d}^{2}}} \) Find d when \( \mathrm{D}=3.6, \mathrm{M}=3 \) and \( \mathrm{w}=2.4 \) giving your answer correct to three significant figures.

II. \( (3+c)^{2} \)

(10) If \( f(x)=2 x+k \) is the inverse function of \( g(x)=m x+3 \), then \( m \times k=-12 \) \( \begin{array}{llll}\text { (a) } 3 & \text { (b) } 6 & \text { (c) }-12 & \text { (d) }-3\end{array} \)

Solve the equation: \( \sqrt[4]{x} + 5 = 7 \)