Angle ACB = 180 - 105 = 75 (LINEAR PAIR POSTULATE)
Angle BAC = 180 - (75 + 75) = 30 (TRIANGLE SUM THEOREM)
Angle BAD + Angle ACD = 180 (SAME SIDE INTERIOR ANGLES THEOREM)
Angle BAD = Angle BAC + Angle CAD (ANGLE ADDITION POSTULATE)
115 + 30 + x = 180
145 + x = 180
x = 180 - 145
x = 35 degrees