Question

решить уравнение
1)log5x^2=0
2)log3x^3=0
3)lgx^4+lg(4x)=2+lgx^3

Answer 1

log(5) x^2=0
log(5) x^2=log(5) 1
x^2=1
x=+-1

log(3) x^3 = 0
log(3) x^3 = log(3) 1
x^3=1
x=1

lg x^4+lg 4x=2+lg x^3
lg x^4+lg 4x=lg 100+lg x^3
x^4*4x = 100*x^3
4x^5= 100x^3
x^5=25x^3
x^2=25
x= +-5