Решите систему уравнений (5x+4)^{2}=9y (4x+5)^{2}=9y

( 5x + 4 )^2 = 9y
( 4x + 5 )^2 = 9y

( 5x + 4 )^2 = ( 4x + 5 )^2
25x^2 + 40x + 16 - 16x^2 - 40x - 25 = 0
9x^2 - 9 = 0
9( x - 1 )( x + 1 ) = 0
X - 1 = 0
X = 1
X + 1 = 0
X = - 1
ответ 1 ; - 1