Question

If 3^(a+b) = 28 and 28^b = 81, find a in terms of b.

Answer 1

one way is to find the value of 28 from second equation :-
28^b = 81

28 = (81)^(1/b)

Answer 2

first equation says :
28 = 3^(a+b)

Answer 3

since left side is same, u can equate the right sides

Answer 4

(81)^(1/b) = 3^(a+b)

see if u can massage this further :)

Answer 5

\(81=3^4\\3^{4/b}=3^{a+b}\\\dfrac{4}{b}=a+b\)
isolate a .DAT SIT