without calculating determine whether each sum is

rational or irrational.
2
1/7
+
3/5
𝜋 + 9

1 answer

To determine whether each sum is rational or irrational without calculating, we can analyze the components of each expression.

  1. The first sum is \( \frac{2}{1} + \frac{1}{7} + \frac{3}{5} \).

    • All of these numbers are rational since they can be expressed as fractions (where the numerator and the denominator are both integers).
    • The sum of rational numbers is always rational.
  2. The second sum is \( \pi + 9 \).

    • Here, \( \pi \) is an irrational number and 9 is a rational number.
    • The sum of a rational number and an irrational number is always irrational.

In conclusion:

  • The first sum \( \frac{2}{1} + \frac{1}{7} + \frac{3}{5} \) is rational.
  • The second sum \( \pi + 9 \) is irrational.