1) (x+5)² - (x - 1)² = 48;
x²+10x+25 - x² +2x - 1 = 48;
12x+24=48
12x=24
x=2
2) (2x - 3)² + (3 - 4x)(x+5)=82;
4x²-12x+9+3x+15-4x²-20x=82
-29x=58
x=-2
3) х (х-3) (4-x) =16-х (х – 3,5)²;
(х²-3x) (4-x) =16-х( х² – 7x + 12. 25)
4х²-12x-х³+3x² = 16-х³+7x²-12. 25x
-12x = 16-12. 25x
0. 25x=16
x=64