I think that the most accurate one is trial 3 since it is the least incorrect and closest percent-wise to the actual correct density of the metal.
Hope this helps!
Sqrt -13 = sqrt13 i
sqrt -26 = sqrt2 * sqrt13i
sqrt-13 * sqrt -26 = sqrt2 * 13* i^2 = -13 sqrt2 (because i^2 = -1)
answer is -13 sqrt2
Triangle BRM = Triangle KYZ
CPCTC ( corresponding parts of congruent triangles are congruent)
if two triangles are congruent then all of their angles and sides are congruent
Make sense?
The answer is the third one