3. Упростите выражение: 1) a) 5(a+2) + (a + 2); 6) (x-3) - 3(x - 3); 2) a) 2x(x+1) - 4x(2-x); 6) 2y(2x-3y) - 3y(5y - 3x); в) 7(x-7) - 3(x-3); г) 15(8x-1) - 8(15x + 4); в) 3c(c + d) + 3d(c - d); r) 5b(3a-b) - 3a(5b + a);

3. Упростите выражение:

1. 1) a)

   5(a+2) + (a + 2) = (5+1)(a+2) = 6(a+2) = 6a + 12

2. 1) 6)

   (x-3) - 3(x - 3) = (1-3)(x-3) = -2(x-3) = -2x + 6

3. 2) a)

   2x(x+1) - 4x(2-x) = 2x^2 + 2x - (8x - 4x^2) = 2x^2 + 2x - 8x + 4x^2 = 6x^2 - 6x = 6x^2 - 6x

4. 2) 6)

   2y(2x-3y) - 3y(5y - 3x) = 4xy - 6y^2 - (15y^2 - 9xy) = 4xy - 6y^2 - 15y^2 + 9xy = 13xy - 21y^2 = 13xy - 21y^2

5. 1) в)

   7(x-7) - 3(x-3) = 7x - 49 - (3x - 9) = 7x - 49 - 3x + 9 = 4x - 40 = 4x - 40

6. 1) г)

   15(8x-1) - 8(15x + 4) = 120x - 15 - (120x + 32) = 120x - 15 - 120x - 32 = -47

7. 2) в)

   3c(c + d) + 3d(c - d) = 3c^2 + 3cd + 3cd - 3d^2 = 3c^2 + 6cd - 3d^2 = 3c^2 + 6cd - 3d^2

8. 2) г)

   5b(3a-b) - 3a(5b + a) = 15ab - 5b^2 - (15ab + 3a^2) = 15ab - 5b^2 - 15ab - 3a^2 = -5b^2 - 3a^2 = -3a^2 - 5b^2