Вправа 483 алгебра Бевз гдз 7 клас
№ 483
а) (x – 3)2 – x(x – 6) = x2 – 6x + 9 – x2 + 6x = 9;
б) (m + 5)2 – (m – 5)2 = m2 + 10m + 25 – m2 + 10m – 25 = 20m;
в) 1 – (2a – 1)2 = 1 – 4a2 + 4a – 1 = 4a – 4a2;
г) z2 + 1 – (1 + z)2 = z2 + 1 – 1 – 2z – z2 = –2z;
ґ) (x – 2)(x – 4) – (x – 6)2 = x2 – 4x – 2x + 8 – x2 + 12x – 36 =
= 6x – 28;
д) (2a – 3c)2 – 3c(3c – 4a) = 4a2 – 12ac + 9c2 – 9c2 + 12ac = 4c2.
вправи поруч
