2^3lgx * 5^lgx = 1600

Question

2^3lgx * 5^lgx = 1600

Answer 1

Lg(2^3lgx)+lg(5^lgx)=3*lgx*lg2+lgx*lg5=lg1600=lg(100*16)=2+lg16,
lgx*(3*lg2+lg5)=2+lg16,
lgx*lg40=lg1600=2*lg40,
lgx=2, x=10²=100. Ответ: x=100.