The image contains a set of mathematical problems involving various topics such as arithmetic operations, factorization, functions, and geometry. Here is a breakdown of the problems:

1. Izračunaj (Calculate):

• a) Two expressions with fractions and basic arithmetic.
• b) A product involving a set of brackets with fractions and decimals.

2. Zapiši u obliku potencije s bazom 3 sljedeće brojeve (Write the following numbers as powers with base 3):

• a) $6 \cdot 3^2 \cdot 9^3$
• b) $2 \cdot 9^4 + 15 - 3^{11} + 2 \cdot 27^4$

3. Provedi kvadriranje (Perform squaring):

• a) $(8a + 3)^2$
• b) $\left(\frac{8}{15} b - \frac{5}{12}\right)^2$

4. Rastavi na faktore sljedeće višelčane izraze (Factorize the following expressions):

• a) $2a - 1(3a + 2) + 2a - 1(2a + 3)$
• b) Complex factorization with multiple variables $a$, $b$, $c$, $x$, etc.

5. Izračunaj (Calculate):

• a) Two fractions added and simplified.
• b) More fraction operations involving $a$, $b$, and constants.

6. Nacrataj graf linearne funkcije (Draw the graph of the linear function):

• A function is provided, and the task is to graph it and calculate the slope.

7. Sustav jednadžbi riješi uvođenjem novih nepoznanica (Solve the system of equations by introducing new unknowns):

• A system of three linear equations is given.

8. Duljine stranica trokuta (Lengths of triangle sides):

• Problems involving the calculation of triangle side lengths, including special cases like right triangles and using trigonometry (sine).

9. Duljina druge katete (Length of the second leg of a right triangle):

• Given one leg and the hypotenuse, calculate the other leg.

10. Odredi koordinatu četvrtog vrha paralelograma (Determine the coordinate of the fourth vertex of the parallelogram):

• Given three coordinates, find the fourth vertex.

Would you like help with a specific problem, or should I go through all of them one by one? Feel free to let me know!