Final answer:
To prove that if a is an irrational number and r is a nonzero rational number, then either ar + s or ar - s is irrational, we can use proof by contradiction.
Step-by-step explanation:
To prove that if a is an irrational number and r is a nonzero rational number, then either ar + s or ar - s is irrational, we can use proof by contradiction.
- Assume that both ar + s and ar - s are rational.
- Since a is irrational and r is rational, then ar is irrational.
- By adding and subtracting a rational number from an irrational number, we cannot obtain two rational numbers.
- This contradicts our assumption, so either ar + s or ar - s must be irrational.