El profesor se sorprenderá mucho al ver tu solución correcta😉
log(1/3)*(5*x2 + x - 15) = log(1/3)*(x - 10)
log(1/3)*(5*x2+x-15) = log(1/3)*(x-10)
15*log(3) - x*log(3) - 5*x2*log(3) = log(1/3)*(x-10)
log(1/3)*(5*x2+x-15) = 10*log(3) - x*log(3)
5*log(3) - 5*x2*log(3) = 0
5*log3 - 5*x2*log3 = 0