Question

пом #5!!!!!!!!!!!!!!!!

Answer 1

1)
m⁻² - n⁻² =(m⁻¹)² - (n⁻¹)²=(m⁻¹ - n⁻¹)(m⁻¹ + n⁻¹)

2)
m⁻² - 2m⁻¹n⁻¹ + n⁻²=(m⁻¹)² - 2m⁻¹n⁻¹ + (n⁻¹)²=(m⁻¹ - n⁻¹)²

3)
[(m⁻¹ - n⁻¹)(m⁻¹ + n⁻¹)]/(m⁻¹ - n⁻¹)² = (m⁻¹ + n⁻¹)/(m⁻¹ - n⁻¹)=
=(1/m + 1/n)/(1/m - 1/n) = [(n+m)/(mn)] / [(n-m)/(mn)]=(n+m)/(n-m)