Answer: -6 and 6
Explanation:
a^2 - 36 = 0
add 36 to both sides
a^2 = 36
square root both sides to get rid of the exponent on the a.
√a^2 = √36
the a^2 and √ cancel out, leaving a = √36
since you squared both sides, the √36 must be +/-
√36 = 6
final solution:
a = +/- 6