164 (5,6,7,8) прошу, помогите мене очень надо :(

Решите задачу:

$(x^2-y^2):(x-y)= \frac{(x-y)(x+y)}{x-y}=x+y\\x=5, y=3\\x+y=5+3=8\\\\(x^2-y^2):x-y= \frac{x^2-y^2}{x}-y \\x=5, y=3\\ \frac{5^2-3^2}{5}-3= \frac{25-9}{5}-3= \frac{16}{5}-3 =3.2-3=0.2\\\\ x^2-y^2:(x-y)=x^2- \frac{y^2}{x-y}\\x=5,y=3\\5^2- \frac{3^2}{5-3}=25- \frac{9}{2}=25-4.5=20,5\\\\ x^2-y^2:x-y=x^2- \frac{y^2}{x}-y\\x=5,y=3\\5^2- \frac{3^2}{5}-3=25- \frac{9}{5}-3=25-1,8-3=20,2$