25^х=5 ^3 - х

3 sin ^2 2x+10sin 2x+3=0

25^x = 5^ (3 - x)

5^ (2x) = 5^ (3 - x)

2x = 3 - x

2x + x = 3

3x = 3

x = 1

3sin²2x + 10sin2x + 3 = 0

3sin²2x + 9sin2x + sin2x + 3 = 0

3sin2x (3sin2x + 3) + (sin2x + 3) = 0

(3sin2x + 1) (3sin2x + 3) = 0

1) 3sin2x = - 1

sin2x = - 1/3

2x = (-1) ⁿ⁺¹arcsin (1/3) + πn, n ∈ Z

x = 1/2· (-1) ⁿ⁺¹arcsin (1/3) + πn/2, n ∈ Z

2) 3sin2x = - 3

sin2x = - 1

2x = - π/2 + 2πk, k ∈ Z

x = - π/4 + πk, k ∈ Z