Solve for x.
Secant - Chord Theorem
8x ( 8x + 6x) = 7 ( 7 + 9)
8x * 14x 7 * 16
112x^2 = 112
112x^2 - 112 = 0
112 ( x^2 - 1) = 0 factor
x^2 - 1 = 0
x^2 = 1
x = 1