дидактические материалы решебник алгебра 7 класс Звавич

с-27

 

1. 1) a) ax + ay + x + y = (ax + ay) + ( + y);
б) a3 + a2 + a - 8x + y = (a2 + a2 + a - 8x) + y;
2) a) ax2 + x + a + 1 = (ax2 + a) + (x + 1);
6) aq2 - q - aq + q2 = (aq2 - aq) + (q2 - q).

2. 1) a) bm - bn - m - n = (bm - bn) - (m + n);
б) bx + by + x - y = (bx + by) - (y - x);
в) ab + ac - b - с = (ab - b) - (c - ac);
2) a) bх - bу - b - х + у + 1 = (bx - by - b) - (x - y - 1);
6) -bx + by + x - y - b + 1 = (-bx + by - b) - (-x + y - 1);
в) -а2 + b2 + 2а - 1 = (b2) - (a2 - 2a + 1).

3. a) ax + by - c - d = (ax + by) - (c + d)
6) 3x - 3y + z - a = (3x + z) - (3y + a)
в) 5x - 3у - z = 5x - (3y + z);
г) -2х + у - z = у - (2х + z).

4. a) (2x2 - 3a + b) - (a - 5x + 1) - (b + x2 - 7x) = 2x2 - 3a + b - a + 5x + 1 - b - x2 + 7x =
= (x2 + 12x) - (a2 + 3a - 1);

6) (8ax2 + 3ab2 - b) - (x2 - ax2 - b) - x = 8ax2 + 3ab2 - b - x2 + ax2 + b - x = (9ax2 - x2 - x) + 3ab2.