7^x-2=4
7^x/7*2=4
7^x/49=4
7^x=49*4
7^x=196
7^x=14^2
7^x=7^2*4 | log in baza 7
x=log in baza 7 din 7^2*4
x= log in baza 7 din 7^2 + log in baza 7 din 4
x=2+log in baza 7 din 4
36^x=16-1/90
36^x=15/90
36^x=1/6
6^2x=6^-1
2x=-1
x=-1/2
4^x²=1
4^x²=4^0
x²=0
x=0
16^x-1=25/100
16^x/16=1/4
16^x=16/4
4^2x=4
2x=1
x=1/2