7. Se vendío un artículo en BS. 450 ganándose el \( 25 \% \) del costo. ¿Cuál sería el precio de venta si se quiere ganar el \( 40 \% \) del costo? \( \begin{array}{lll}\text { a) } B 5.520 & \text { b) } 540 & \text { c) } 504 \\ \text { d) } 480 & \text { e) } 490 & \end{array} \)

Solve the equation \( \frac{1}{2} x^{2}+x-\frac{1}{10}=0 \)

1 2 Write both numbers as products of their primes. 3 Use your results from 6.1 to determine the HCF of 12 and 16 Use your results from 6.1 to determine the LCM of 12 and 16 .

25. In the diagram below, \( A P B \) is a straight line. \( \angle A B C=90^{\circ}, A C=17 \mathrm{~cm}, A P=9 \mathrm{~cm} \) and area of \( \triangle A P C=36 \mathrm{~cm}^{2} \). Calculate (a) the length of \( B C \),

4) \( \frac{m-2}{m-5}:\left(\frac{m^{2}+24}{m^{2}-25}-\frac{4}{m-5}\right) \)

What is the value of \( \sqrt{-1} \) ?