24) (3x+30)²-9x²=0
(3x+30-3x)(3x+30+3x)=0
30(6x+30)=0
6x=-30
x=-5
31) log₈(2x-4)+log₈3=log₈9
log₈3(2x-4)=log₈9
3(2x-4)=9
2x-4=3
2x=7
x=3,5
32) log₇(2x-4)+log₇4=log₇8
log₇4(2x-4)=log₇8
4(2x-4)=8
2x-4=2
2x=6
x=3
33) 1/√x=1/5
√x=5
x=25
35) 1/√x=1/4
√x=4
x=16