Answer:
C
Explanation:
Given 2 chords intersecting inside a circle, then
the product of the measures of the parts of one chord is equal to the product of the measures of the parts of the other chord, that is
12(4x + 1) = 14(3 + 3x) ← distribute parenthesis on both sides
48x + 12 = 42 + 42x ( subtract 42x from both sides )
6x + 12 = 42 ( subtract12 from both sides )
6x = 30 ( divide both sides by 6 )
x = 5