1. The problem is to add two fractions, for example, $\frac{a}{b} + \frac{c}{d}$.\n\n2. The formula to add fractions is:\n$$\frac{a}{b} + \frac{c}{d} = \frac{ad + bc}{bd}$$\nThis means you multiply the numerator of the first fraction by the denominator of the second, and the numerator of the second fraction by the denominator of the first, then add those two products together for the new numerator. The new denominator is the product of the two denominators.\n\n3. Important rule: The denominators must be non-zero. Also, if possible, simplify the resulting fraction by dividing numerator and denominator by their greatest common divisor (GCD).\n\n4. Example: Add $\frac{2}{3} + \frac{1}{4}$.\nCalculate numerator: $2 \times 4 + 1 \times 3 = 8 + 3 = 11$.\nCalculate denominator: $3 \times 4 = 12$.\nSo, $\frac{2}{3} + \frac{1}{4} = \frac{11}{12}$.\n\n5. The final answer is $\frac{11}{12}$.