1. The problem is to express the fraction $\frac{7}{20}$ as a decimal using long division. 2. The formula or method used here is long division, where we divide the numerator (7) by the denominator (20). 3. Set up the division: 7 divided by 20. Since 7 is less than 20, we add a decimal point and zeros to 7 to continue the division. 4. Divide 70 by 20: 20 goes into 70 three times (3 x 20 = 60). Write 3 after the decimal point. 5. Subtract 60 from 70: 70 - 60 = 10. 6. Bring down another zero to make 100. 7. Divide 100 by 20: 20 goes into 100 five times (5 x 20 = 100). Write 5 after the 3. 8. Subtract 100 from 100: 0, so the division ends. 9. The decimal representation of $\frac{7}{20}$ is $0.35$. Therefore, $\frac{7}{20} = 0.35$.