㏒ ₂ y + ㏒ ₂ 3 = ㏒ ₂ x
㏒ ₂ 3y = ㏒ ₂ x
3y = x
y > 0 ; x > 0
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3 ^ x * 3 ^ y^2 = 81
3 ^ ( x + y^2 ) = 3 ^ 4
x + y^2 = 4
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3y + y^2 = 4
y^2 + 3y - 4 = 0
D = 9 + 16 = 25 = 5^2
y1 = ( - 3 + 5 ) : 2 = 1
y2 = ( - 3 - 5 ) : 2 = - 4 ( < 0 )
x = 3y
x = 3
Ответ ( 3 ; 1 )