How to.do?

Please read :

http://imgur.com/a/EjzQ9

log3 (3x+10) - 1 = log(3x+10) /log(3) - 1
log2 3 = log(3) /log(2)
log3 3x = log(3x) /log(2)


log(3x+10) /log(3) - 1 = 3 log(2) / log(3) - log(3x) /log(3)
log(3x+10) /log(3) - log(3)/log(3) = log(2^3) /log(3) - log(3x)/log(3)
multiply everything by log(3)

log(3x+10) - log(3) = log(8) - log(3x)
log( (3x+10) /3) = log ( 8/3x)

(3x+10)/3 = 8/ 3x

cross multiply
3x(3x+10) = 24
9x^2+30x-24=0
3x^2+10x-8=0
3x^2+12x-2x-8=0
3x(x+4)-2(x+4)=0
(x+4)(3x-2) = 0
x+4 = 0
x= -4 (not a solution because log(3x+10) woul become log(-12+10) = log(-2)
(log of a negative number)
3x-2 = 0
x= 2/3