Answer:
KM = 20
Explanation:
Point V is the midpoint of KM, so ...
KV = VM
2.5z = 5z -10
10 + 2.5z = 5z . . . . . add 10
10 = 2.5z . . . . . . . . . subtract 2.5z
This is sufficient to answer the question:
KV = VM = 2.5z = 10
KM = KV + VM = 10 + 10
KM = 20
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In this case, it is not necessary to find the value of z. If you wanted to, you could divide by the coefficient of z in the last equation:
10/2.5 = z = 4