Question

Find x, if :  log_x 625 = - 4

Answer 1

log_x 625 = - 4

⇒ 625 = x^{- 4}          ...[ Removing logarithm ]

⇒ 5⁴ = `( 1/x )^4`
⇒ 5 = `1/x`           ....[ Powers are same, bases are equal ]
⇒ x = `1/5`