1)(9+a)²; 2)(8-6)²; 3)(3-4)²; 4)(5a +6b)²;​

1) (9+a)^2 = 81 + 18a + a^2

2) (8-6)^2 = 4

3) (3-4)^2 = -1

4) (5a + 6b)^2 = 25a^2 + 60ab + 36b^2