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Logarithms

Aatikah1

Does anyone know how to solve the simultaneous equasions?

9^x-2 = 3^y
And
Log3(2x) = 1 + log2(y)

Reply 1

RDKGames

Study Forum Helper

Original post by Aatikah1

Does anyone know how to solve the simultaneous equasions?

9^x-2 = 3^y
And
Log3(2x) = 1 + log2(y)

From the first equation, note that 9 = 3^2 so 9^(x-2) becomes 3^(2x-4). Since this is equal to 3^y, we have that y = 2x-4.

Sub into the second eq. and solve from there.

Reply 2

Aatikah1

Original post by RDKGames

From the first equation, note that 9 = 3^2 so 9^(x-2) becomes 3^(2x-4). Since this is equal to 3^y, we have that y = 2x-4.

Sub into the second eq. and solve from there.

Wait im sorry but how did you get 9=3^2?