Answer:
Correct answer is B. 16
Explanation:
In a parallelogram, the diiagonals cut each other into two equal parts,
which means AE = CE
Given AE = x∧2 - 8 and CE = 2x
AE = CE => x∧2 -8 = 2x => x∧2 -2x -8 = 0
this is qudratic equation and we will factorize it and solve it:
x∧2 -4x + 2x -8 = (x∧2 - 4x) + (2x - 8) = x(x-4) + 2(x-4) = (x-4) · (x+2) = 0
x-4 = 0 and x+2 = 0 => x=4 and x= -2
We will accept first solution (because it is positive) x = 4
AE = CE = 2x = 2 · 4 = 8 or AE = CE = x∧2 - 8 = 4∧2 - 8 = 16 - 8 = 8
AC = AE + CE = 8 + 8 = 16 => AC = 16
God with you!!!