for integers a and b if (a^3 - a^2 - b)^.5 = 7,
what is the value of a?
1)a^2 - a =12
2)b^2 - b = 2
OA: b
what is the value of a?
1)a^2 - a =12
2)b^2 - b = 2
OA: b
IMO B:
(a^3 - a^2 - b)^.5 = 7
or (a^3 - a^2 - b) = 49
A: a^2 - a =12 => a^2 - a - 12 = 0 => a = 4 or a = -3. Not sufficient
B: b^2 - b = 2 => b = 2 or b = -1
if b = 2, a^3 - a^2 = 51. This doesn't give an integer value for a.
if b = -1, a^3 - a^2 = 48 => a = 4. Sufficient
Hope this helps
