Solve the following exponential equations.

8(6^2x+5)=7^3x-4

taking it as written, I can't see an easy symbolic solution

8*6^2x + 40 = 7^3x - 4

assuming sloppy parentheses, and you meant

8*6^(2x+5) = 7^(3x+4)

then take logs of both sides:

log8 + (2x+5)log6 = (3x-4)log7
log8 + 2x log6 + 5log6 = 3x log7 - 4log7
(2log6 - 3log7)x = -(4log7 + 5log6 + log8)

x = log149361408/log12348 = 1.9978