Question

Solve for a.

(a+6)^2=49


A −13 and 1

B −3 √6 and 3 √6

C −1 and 13

D −√43 and √43

Answer 1

(a+6)^2 = 49
(a+6)(a+6) = 49
a^2 + 6a + 6a + 36 = 49
a^2 + 12a - 13 = 0
(a-1)( a+13) = 0

a-1 =0
a = 1

a+13= 0
a = -13

The answer is A.