1. **State the problem:** Simplify the expression $\frac{7}{10} - \left(-\frac{1}{2}\right)$. 2. **Recall the rule:** Subtracting a negative number is the same as adding its positive counterpart, so $a - (-b) = a + b$. 3. **Apply the rule:** $\frac{7}{10} - \left(-\frac{1}{2}\right) = \frac{7}{10} + \frac{1}{2}$. 4. **Find a common denominator:** The denominators are 10 and 2. The least common denominator (LCD) is 10. 5. **Convert fractions:** $\frac{7}{10}$ stays the same, and $\frac{1}{2} = \frac{5}{10}$. 6. **Add the fractions:** $\frac{7}{10} + \frac{5}{10} = \frac{7+5}{10} = \frac{12}{10}$. 7. **Simplify the fraction:** $\frac{12}{10} = \frac{6}{5} = 1 \frac{1}{5}$. **Final answer:** $\frac{7}{10} - \left(-\frac{1}{2}\right) = \frac{6}{5}$ or $1 \frac{1}{5}$.