Find all values of c such that 3^(2c+1) = 28*3^c
3^(2c + 1) = 28*3^c
3^(2c) * 3^1 = 28*3^c
(3^c)^2 * 3 = 28 *3^c divide both sids by 3^c
3^c * 3 = 28
3^c = 28/3 take the log of each side
log 3^c = log (28/3)
c * log 3 = log (28/3)
c = log (28/3) / log (3)