Step-by-step explanation:
1.7) x = √y
The square root must be non-negative, so the domain is x ≥ 0, or in interval notation, [0, ∞).
1.8) s = (2r − 5) / (3r)
The denominator can't be 0, so r can't be 0. So the domain is r ≠ 0, or in interval notation, (-∞, 0) (0, ∞).
1.9) ab = 12
Solve for b: b = 12/a
The denominator can't be 0, so a can't be 0. So the domain is a ≠ 0, or in interval notation, (-∞, 0) (0, ∞).
