решебник алгебра 7 класс Звавич

с-35

 

1. 1) a) a(b + c) + p(b + c) = (b + c)(a + p);
6) a(x - y) - b(x - y) = (x - y)(a - b);
в) 3а(a + b) - m(a + b) = (a + b)(3a - m);
г) 7(x - c) + (x - c)xc = (x - c)(7 + xc);
2) а) а(x - 2) + (x - 2) = (x - 2)(а + 1);
6) (c + 8) - с(с + 8) = (с + 8)(1 - с);
3) а) 2(a - 3) + b(3 - а) = (b - 3)(2 - b);
б) 3(b - 5) - а(5 - b) = (b - 5)(а + 3);
4) а) x(а - 5) + (5 - а) = (а - 5)(x - 1);
б) m - n + (n - m)у = (m - n)(1 - у).

2. 1) a) x(a + b) + c(a + b) = (a + b)(x + c);
б) 3(а - с) + х(а - с) = (а - с)(х + 3);
2) a) 4(a + b) + y(a + b) = (a + b)(y + 4);
6) 6(x + 7) + y(x + 7) = (x + 7)(y + 6);
3) a) p(x + y) - 5(x + y) = (x y)(p - 5);
6) a(b - c) - 4(b - c) = (b - c)(a - 4).

3. 1) a) 2a + b + 2a2 + ab = 2a(1 + a) + b(1 + a) = (a + 1)(2a + b);
6) 3a + 3a2 - b - ab = 3a(1 + a) - b(1 + a) = (a + b)(3a - b);
в) 2x2 - 3x + 4ax - 6а = x(2x - 3) + 2a(2x - 3) = (2x - 3)(x + 2a);
г) x2yz + xy + axy + a = xy(xy + 1) + a(xy + 1) = (xy + 1)(xy + a);
2) a) ab + ac + am + yb + yc + ym - b (a + y) + с (a + y) + m(a + y) = (a + y)(b + с + m);
6) xy - x2у2 + x3у3 - a + axy - ax2у2 = xy(1 - xy + x2у2) - a(1 - xy + x2y2) = (1 - xy + x2y2)(xy - a);
3) a) bn + 1 + bn + b + 1 = bn(b + 1) + b + 1 = (b + 1)(bn + 1);
6) am+2 - 1 - a + am+1 = am+1(a + 1) - (a + 1) = (a + 1)(am+1 - 1).

4. a) x2 + x + 2x + 2 = x(x + 1) + 2(x + 1) = (x + 1)(x + 2);
6) x2 - 3x - 2x + 6 = x(x - 3) - 2(x - 3) = (x - 3)(x - 2).