The fractional part of the number \(\tfrac{4^{2022}}{15}\) is equal to:
If the equation of the normal to the curve \( y = \frac{x - a}{(x + b)(x - 2)} \) at the point \( (1, -3) \) is \( x - 4y = 13 \), then the value of \( a + b \) is: