Answer:
The number next to a variable is called the Coefficient of the variable.
Cos x = 8/13 = 52
So your answer is 52.
It is definitely a reflection over the horizontal (x) axis, but i think the dilation is by 2
Look into my attachment
in rhombus ABCD, ∠AOB = 90°
Look at ΔAOBthe sum of inner angles = 180°
∠BAO + ∠AOB + ∠ABO = 180°
2x + 1 + 90 + 2x + 5 = 180°
4x + 96 = 180
4x = 84
x = 21