№ 658
а) (х – 3)2 – х(х + 4) = –1x2 – 6x + 9 – x2 – 4x + 1 = 0–10x = –10x = 1;
б) (4х + 5)(х – 2) – (2х – 1)2 = –94x2 – 8x + 5x – 10 – 4x2 + 4x – 1 + 9 = 0x = 2.
вправи поруч