Назад
ГДЗ Алгебра 7 клас Мерзляк (2024)
§ 1. Алгебраїчні вирази
Реклама:
Спростіть вираз:
1) (y – 9)2 + (4 – y)(y + 6) = y2 – 18y + 81 + 4y + 24 – y2 – 6y = –20y + 105;
2) (x –4)(x + 4) – (x – 1)2 = x2 – 16 – (x2 – 2x + 1) = x2 – 16 – x2 + 2x – 1 = 2x – 17;
3) (2a – 3b)2 + (3a + 2b)2 = 4a2 – 12ab + 9b2 + 9a2 + 12ab + 4b2 = 13a2 + 13b2;
4) (x – 5)2 – (x – 7)(x + 7) = x2 – 10x + 25 – (x2 – 49) = x2 – 10x + 25 – x2 + 49 = –10x + 74.
1) (y – 9)2 + (4 – y)(y + 6) = y2 – 18y + 81 + 4y + 24 – y2 – 6y = –20y + 105;
2) (x –4)(x + 4) – (x – 1)2 = x2 – 16 – (x2 – 2x + 1) = x2 – 16 – x2 + 2x – 1 = 2x – 17;
3) (2a – 3b)2 + (3a + 2b)2 = 4a2 – 12ab + 9b2 + 9a2 + 12ab + 4b2 = 13a2 + 13b2;
4) (x – 5)2 – (x – 7)(x + 7) = x2 – 10x + 25 – (x2 – 49) = x2 – 10x + 25 – x2 + 49 = –10x + 74.