Answer:
a = + or - sqrt(7)/6, which are irrational ( Answer Choice (b) ) for either case.
Step-by-step explanation:
a^2 = 7/36 implies that
a^2 - 7/36 = 0, by subtracting 7/36 from both sides of the equation, which implies that
(a - sqrt(7)/6)(a + sqrt(7)/6) = 0, by factoring, which implies that
a - sqrt(7)/6 = 0 or a + sqrt(7)/6 = 0, by the zero product property of the real number system, which implies that
a = sqrt(7)/6 or a = - sqrt(7)/6, which are both irrational, since sqrt(7) is irrational and an irrational number divided by an integer (other than 0) is irrational.