(3x-1)²+(4x+2)²=(5x-1)•(5x+1)
(3x-1)²+(4x+2)² - (5x-1)•(5x+1) = 0
9x²-6x+1 + 16x²+16x+4 - (25x²-1) = 0
25x²+10x+5 - 25x²+1 = 0
10x = - 6
x = - 6 : 10
x = - 0,6