Вправа 497 алгебра Бевз гдз 7 клас
№ 497
а) (x – 6)2 + (2x + 3)2 = 5x(x – 9)
x2 – 12x + 36 + 4x2 + 12x + 9 = 5x2 – 45x
5x2 – 5x2 + 45x = –45
x = –45 : 45
x = –1;
б) 2(3 – x)2 – x(x + 6) = (x – 4)2
18 – 12x + 2x2 – x2 – 6x = x2 – 8x + 16
–10x = –2
x = –2 : (–10)
x = 0,2.
вправи поруч
