Please help!! Use rhombus ABCD and the given information to solve #15-18.
15) If mZBFC = (8x - 4)º, find x. 16) If mZBAF = 31°, find mZBCA. 17) If AB = 7x - 12 and BC = 8x - 22, find AD. 18) If mZADB =(x- 15)° and mZCDB = (2x), find the value(s) of x.