Answer:
n = 6
Step-by-step explanation:
Two intersecting chords. The product of the parts of one chord is equal to the product of the parts of the other chord, that is
7(n + 4) = 5(n + 8) ← distribute parenthesis on both sides
7n + 28 = 5n + 40 ( subtract 5n from both sides )
2n + 28 = 40 ( subtract 28 from both sides )
2n = 12 ( divide both sides by 2 )
n = 6
