Question

Alejandra was given this problem to solve her math classz x ^ 2 + 9 = 0. She realized that both x ^ 2 and 9 are perfect squares . Therefore Alejandra chose to use difference of squares and completed the problem as such. (x + 3)(x - 3) = 0 x = - 3 and x = 3 Explain why Alejandra was incorrect in choosing to use the difference of squares method. (Explain why she could not use the difference of square method x ^ 2 + 9 = 0)

Answer 1

see below

Explanation:

x ^ 2 + 9 = 0

difference of squares method

Difference means subtraction

x^2 - b^2 = (x-b) (x+b)

We do not have the difference of squares

x^2+9=0

x^2 = -9

This means we do not have a real solution