(2x-7)×(x+1)+3×(4x-1)×(4x+1)=2×(5x-2)(в квадрате)-53

(2x-7)(x+1)+3(4x-1)(4x+1)=2(5x-2)²-532x²-7x+2x-7+48x²+12x-12x-3=2(25x²-10x+4)-5350x²-5x-10=50x²+20x+8-5350x²-5x-10-50x²-20x-45=0-25x-55=0/-55x+11=05x=-11x=-11/5x= -2,2