Slove for x.
A.11
B.9
C.13
D.14

Step-by-step 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

I think I've done this correctly. If you find an error, please let me know and I'll open it for editing.

how is that middle school

step-by-step explanation: