Log5 (3+x^2) = log2 28

Log5 (3+x^2) = log2 (28)

Одз: 3+х²>0; х²> - 3 (всегда)

log5 (3+x²) = log2 (7·4)

5^ (log2 (7·4)) = 3+x²

5^ (log2 (4) + log2 (7)) = 3+x²

5^ (2+log2 (7)) = 3+x²

5²·5^log2 (7) = 3+x²

5²·5^log2 (7) - 3 = x²

± (5²·5^log2 (7) - 3) ^½ = x²