a)
[tex]R = \frac{U}{I} | \times I \\ U = R \times I | \div R \\ I = \frac{U}{R} [/tex]
b)
[tex]I = \frac{q}{t} | \times t \\ q = I \times t | \div I \\ t = \frac{q}{I} [/tex]
c)
[tex]U = \frac{W}{q} | \times q \\ W = U \times q | \div U \\ q = \frac{W}{ U}[/tex]
