Question

A2-b2 и a2-2ab+b2 при a=2; b=-5

Answer 1

2^2-5^2
2^2-2*2*5+5^2
4-20+25=9

Answer 2

To evaluate the expressions A^2 - B^2 and A^2 - 2AB + B^2 with a = 2 and b = -5, we can substitute the given values into the expressions.

1. A^2 - B^2: Substitute a = 2 and b = -5 into A^2 - B^2: A^2 - B^2 = (2)^2 - (-5)^2 = 4 - 25 = -21

2. A^2 - 2AB + B^2: Substitute a = 2 and b = -5 into A^2 - 2AB + B^2: A^2 - 2AB + B^2 = (2)^2 - 2(2)(-5) + (-5)^2 = 4 + 20 + 25 = 49

Therefore, when a = 2 and b = -5, the values of A^2 - B^2 and A^2 - 2AB + B^2 are -21 and 49, respectively.