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4.3 Equations Involving Indices

METHOD:
  1. Comparison of indices or base
    1. If  the base are the same , when a x = a y , then x = y
    2. If  the index are the same , when a x = b x , then a = b
  2. Using common logarithm (If base and index are NOT the same)
a x = b           ⇒         lg a x = lg b                                                                     x = lg b lg a


Example 1 (Index Equation – Equal base)
Solve each of the following.
(a) 16 x = 8
(b) 9 x .3 x − 1 = 81
(c) 5 n + 1 = 1 125 n − 1




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