The value of 18^ is

Step-by-step solution

aligned & 90^ = 5 (81^ ) and let 18^ = A & 90^ = 5 ~A = (3 ~A +2 ~A ) & 90^ =3 ~A +2 ~A (90^ -3 ~A )= 2 ~A & 2 ~A - 3 ~A 2 A A =4 ^3 ~A -3 A & A (2 A -4 ^2 ~A +3 )=0 & A =0 or [2 A -4 (1- ^2 ~A )+3 ]=0 & A = 2 or 4 ^2 ~A +2 A -1=0 aligned Since, A=18^ , A 2 aligned & 4 ^2 ~A +2 A -1=0 & A = -2 4+16 2(4) = -2 20 8 = 2- 2 5 8 = -1 5 4 & A = -1+ 5 4 or A = -1+ 5 4 aligned Since, A >0, A = 5 -1 4