(2х+1)^2-3(х-5)^2=(х+3)(х-3)
(4x²+4x+1)-3(x²-10x+25)=x²-9 4x²+4x+1-3x²+30x-75=x²-9 x²+34x-74=x²-9 x²+34x-74-x²+9=0 34x=63 x=63/34