Respuesta :

rspill6

Answer:

D.  x = -9

Step-by-step explanation:

We want -(3/7) = (x/21)

Cross multiply:  7x = - 63

x = - 9

Check:

Does (-9/21) = -(3/7)?

(-9/21) reduces to -(3/7)   YES
D because you would cross multiply 7 and x which would give u -63 making x = -9. -9/21 simplifies down to -3/7.