a) \( \left(\frac{25}{3}\right)^{\frac{1}{2}}-\left(\frac{1}{3}\right)^{-\frac{1}{2}} \)

20 If \( \frac{a}{b}=\frac{c}{d}=\frac{3}{5} \), then \( \frac{a+c}{b+d}=\ldots \ldots \ldots \ldots \) \( \begin{array}{llll}\text { (a) } \frac{5}{3} & \text { (b) } \frac{3}{5} & \text { (c) } \frac{6}{5} & \text { (d) } \frac{5}{6}\end{array} \)

13 If \( \frac{a}{b}=\frac{b}{c}=2 \), then \( \frac{a}{c}=\ldots \ldots \ldots \ldots \) \( \begin{array}{lll}\text { (a) } 2 & \text { (b) } 4 & \text { (c) } 6\end{array} \)

\( 67.04 \mathrm{~cm}^{2}=\frac{\sqrt{269}}{2} h \) what is h ?

\( 67.04 cm ^ { 2 } = \frac { \sqrt { 26 a } } { 2 } h \)

23. Find the equation of a line. Whose intercepts on \( x \) and \( y \) axis are 4 and -6 .