Решите пожалуйста, очень срочно надо!

1
[(a+3)^2+(a-3)^2]/(a-3)(a+3)=(a^2+6a+9+a^2-6a+9)/(a^2-9)=2(a^2+9)/(a^2-9)
2(a^2+9)/(a^2-9) * (9-a^2)/3(a^2+9)=-3/2
2
(5x^2+5x-10x)/(x+1) * 4(x+1)/15(x-1)=5x(x-1)/(x+1) * 4(x+1)/15(x-1)=4x/3
3
(a+2)/5(a-4) * 240/a(a+2)=48/a(a-4)
3a/(a-4) - 48/a(a-4)=(3a^2-48)/a(a-4)=3(a-4)(a+4)/a(a-4)=(3a+12)/a
4
8b/(b+7) - 15b/(b+7)^2=(8b^2+56b-15b)/(b+7)^2=b(8b+41)/(b+7)^2
b(8b+41)/(b+7)^2 * (b-7)(b+7)/(8b+41)=(b^2-7b)/(b+7)
(b^2-7b)/(b+7)+(7b-49)/(b+7)=(b^2-7b+7b-49)/(b+7)=(b-7)(b+7)/(b+7)=b-7