Log7(12.25)+log7(4)= 3^(2x-16)=1/81 18=1500*(x-496)/(x+496)

... = log(7)(12.25*4) = log(7)(49) = 2

1/81 = 3^(-4)
2x-16 = -4
2x = 12
x = 6

x ≠ -496
6 = 500*(x-496) / (x+496)
6x + 6*496 = 500x - 500*496
x*494 = 496*506
x = 496*506 / 494 = 248*506 / 247 = (1_1/247)*506 =
= 506 + 506/247 = 506 + 2_12/247 = 508 целых 12/247