5(3 - 5a)^2 - 5(3a - 7)(3a + 7) (a + 1)^2 + 3(a - 1)^2 - 5(a +1)(a - 1)

Question

5(3 - 5a)^2 - 5(3a - 7)(3a + 7)

(a + 1)^2 + 3(a - 1)^2 - 5(a +1)(a - 1)

Answer 1

1)    5(9-30a+25a^2)-5(9a^2-49)=45-150a+125a^2-45a^2+245=80a^2-150a+290=10(8a^2-15a+29).

 

2)   (a^2+2a+1)+3(a^2-2a+1)-5(a^2-1)=a^2+2a+1+3a^2-6a+3-5a^2+5=-a^2-4a+9