help me pleaseeeeeeee!!!!!!!!

Answer:
8
Step-by-step explanation:
Using the chord chord theorem
10(4) = 5x
Solve for x
Simplify multiplication
40 = 5x
Divide both sides by 5
40/5 = 8
5x/5 = x
We're left with x = 8
Note:
Chord chord theorem states that if two chords intersect then the product of the measures of each part of one chord is equal to the product of the measures of the parts of the other chord.
Because the chords shown intersect the product of the parts of each chord should be equal to each other ( 4 * 10 = 5x )
Source: https://www.dummies.com/education/math/geometry/how-to-use-the-chord-chord-power-theorem