4^x = 7^(x-2) is the proper way to express this. Please drop the "zhskdhdvdjd in dve," as it is totally irrelevant here.
Express 4 as e^(ln 4) and 7 as e^(ln 7). Then
4^x = 7^(x-2) becomes x*e^(ln 4) = (x-2)*e^(ln 7) = x*e^(ln 7) - 2*e^(ln 7)
Solving for x: x [ e^(ln 4) -e^(ln 7) ] = -2*e^(ln 7)
-2(7) -14
x = ---------------- = ----------- = 14/3 (answer)
(4) - (7) -3