EXPONENTIALS 7

If 8²⁰ = 32^a-2; find a.

Solution

8²⁰ = 32^a-2 

(2³)²⁰ = (2⁵)^a-2 

2⁶⁰ = 2^5(a-2) 

2⁶⁰ = 2^5a-10

2⁶⁰ = 2^5a-10      [Same bases both sides, cancel out]

60 = 5a – 10

60 + 10 = 5a

70 = 5a

70 = 5a

5      5

14 = a

Hence a=14

TRY THIS……………………….

If 4⁷ = 64^y-2; find y.