ГДЗ Математика 7 клас Істер (2024)

Подайте вираз у вигляді добутку:

1) a2 – 81 + a – 9 = (a2 – 92) + (a – 9) = (a – 9)(a + 9) + (a – 9) = (a – 9)(a + 9 + 1) = (a – 9)(a + 10);
2) m2 – a2 – (a + m) = (m – a)(m + a) – (m + a) = (m + a)(m – a – 1);
3) x2 – y2 – x + y = (x2 – y2) – (x – y) = (x – y)(x + y) – (x – y) = (x – y)(x + y – 1);
4) x + x2 – y – y2 =(x2 – y2) + (x – y) = (x – y)(x + y) + (x – y) = (x – y)(x + y + 1);
5) a – 3b + a2 – 9b2 = (a – 3b) + (a2 – 9b2) = (a – 3b) + (a – 3b)(a + 3b) = (a – 3b)(1 + a + 3b);
6) 16m2 – 25n2 – 4m – 5n = (16m2 – 25n2) – (4m + 5n) = (4m – 5n)(4m + 5n) – (4m + 5n) = (4m + 5n)(4m – 5n – 1).