K2=225

a) k=13
b) k=(-13)
c) k=15
d) k=(-15)

This is basically a direct proportion equation,

y = kx

in this case, it’s :

225 = k2

to get k, we have to divide 225 by 2 hence:

112.5 = k
k = 112.5

Since the answer match none of the multiple choice you provided.

You must’ve written the question wrongly, if you were writing to the power of 2, it means u should have written k^2 = 225.

In this case, it’s not a direct proportion question and it’s a case of simple algebraic equation.

k^2 = 225
Then
k = +/- 15.

Hence the answer is both C and D