Answer:
Explanation:
The secants form a proportion where the full length of the secant is the denominator of a fraction where the numerator is the external part of the secant.
7/(x + 7) = 6/(15 + 6) Cross Multiply after combining
7 / (x + 7) = 6/(21)
6 * (x + 7) = 7 * 21 Remove the brackets
6x + 42 = 147 Subtract 42
6x = 147 - 42
6x = 105 Divide by 6
x = 17.5
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