16-x^2=0
(4+x)(4-x)=0
4+x= 0 или 4-х=0
Х1=-4. Х2=4
3х^2-75=0
3х^2=75
x^2=75:3
х^2=25
X1=5 X2=-5
9+ 99/99 = 10 99/9 – 9/9 = 10.........
а)log₃81=4